JPH11210413A - Manufacture of camshaft, cam lobe positioning device, and camshaft manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a problem of the occurrence of tempering by heating an outer peripheral face of a cam lobe to a quenching temperature and fitting a shaft into a shaft fitting hole of the cam lobe after heating an inner peripheral face of the shaft fitting hole of the cam lobe up to a shrink fit temperature when the shaft is shrink fitted into the shaft fitting hole of the cam lobe. SOLUTION: When a shaft is shrink fitted into a cam lobe 11, the cam lobe 11 is first placed on a reference plate 20a provided on a jig foundation 20, and a center pin 22 is fitted in a shaft fitting hole 12. Moreover, a phase determining pin 24 is fitted into an insertion hole 13 to position and fix it. Two clampers 25 are operated in this state to press the cam lobe 11 from above, and then an outer peripheral face of the cam lobe 11 is heated up to a quenching temperature through a high frequency coil 26 and an inner peripheral face of a shaft fitting hole 12 is heated up to a shrink fitting temperature. Then, a shaft 16 held by a chuck 19 is lowered and is fitted into the shaft fitting hole 12 of the cam lobe 11 to integrate the cam lobe 11 with the shaft 16 by shrink fitting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a camshaft by assembling a shaft into a shaft insertion hole of a camrob by shrink fitting, an apparatus therefor, and a cam lob positioning jig used for manufacturing the camshaft.

[0002]

2. Description of the Related Art When manufacturing a camshaft used for an internal combustion engine, there is a method of integrally casting the cam lobe and the shaft. However, in order to reduce the weight and reduce the manufacturing cost, the cam lobe and the shaft are generally combined. Are manufactured separately, and the two are combined and integrated to form a camshaft.

Although there is a method of brazing the cam lobe and the shaft by brazing (Japanese Patent Laid-Open No. Hei 6-193708), the cam lob and the shaft are fitted to each other by fitting such as interference fitting which is lower in cost than brazing. A method of performing integration with a shaft is also known (Japanese Patent Laid-Open No. 61-6338).
No. 3, JP-A-6-330108).

As another method of integrating the cam lobe and the shaft, there is a method of shrink fitting. In this shrink fitting, first, the cam lobe is heated to the shrink fitting temperature, and then the shaft at room temperature is fitted into the shaft fitting hole of the cam lobe.
Then, by cooling the whole, the diameter of the shaft fitting hole is reduced, and the cam lobe and the shaft are fitted and integrated.

[0005]

However, when the cam lobe and the shaft are integrated by shrink fitting, the following problems arise.

That is, since the outer peripheral surface of the cam lobe is used as a sliding surface, it must be hardened by quenching. Therefore, in the manufacture of camshafts,
The outer peripheral surface of the cam lobe is hardened by previously heating the outer peripheral surface of the cam lobe to a quenching temperature and cooling. When the cam lobe hardened by quenching in this way is reheated in order to shrink fit on the shaft, tempering occurs,
In some cases, the hardness of the outer peripheral surface of the cam lobe was reduced.

In this reheating, it is necessary to heat the cam lobe to a temperature considerably higher than the shrink-fitting temperature required at the time of fitting the shaft in consideration of the fact that the cam lobe is cooled by heat radiation until the shaft is fitted. For this reason, tempering of the outer peripheral surface of the cam lobe was more likely to occur.

The present invention relates to a method for manufacturing a camshaft by assembling a shaft into a shaft insertion hole of a cam lobe by shrink fitting, wherein the method does not affect quenching of the outer peripheral surface of the cam lobe, and is used in this cam shaft manufacturing method. It is an object of the present invention to provide a camshaft manufacturing apparatus and a cam lobe positioning jig which are used.

[0009]

According to a first aspect of the present invention, there is provided a method of manufacturing a camshaft, the method comprising manufacturing a camshaft by assembling a shaft into a shaft fitting hole of a camrob by shrink fitting. A heating step of heating the inner peripheral surface of the shaft fitting hole of the cam lobe to the shrink fitting temperature while heating to the insertion temperature, and a fitting step of fitting a shaft into the shaft fitting hole of the cam lobe heated in the heating step. It is characterized by performing.

That is, first, as a heating step, the outer peripheral surface of the cam lobe is heated to the quenching temperature and the inner peripheral surface of the shaft insertion hole of the cam lobe is heated to the hardening temperature. Since the shrink fitting temperature is lower than the quenching temperature, for example, if the outer peripheral surface is heated to a quenching temperature by a method capable of raising the temperature from the outer peripheral surface of the cam lobe, heat transfer from the outer peripheral surface to the inner peripheral surface Naturally, the temperature of the inner peripheral surface of the shaft fitting hole present inside the cam lobe can be adjusted to the shrink fitting temperature.

In this state, when the fitting step is performed and the shaft is fitted into the shaft fitting hole heated to the shrink fitting temperature, the shaft absorbs the heat of the cam lobe from the inner peripheral surface side of the shaft fitting hole, and the temperature of the cam lobe is reduced. Decreases rapidly and the temperature of the shaft increases. Thus, the cam lobe and the shaft are shrink-fitted and integrated. Further, the outer peripheral surface of the cam lobe is also rapidly deprived of heat from the shaft insertion hole side by heat conduction, and the temperature rapidly decreases from the quenching temperature. This hardens the outer peripheral surface of the cam lobe. If the cooling speed due to the insertion of the shaft is insufficient, the entire camshaft in which the cam lobe and the shaft are integrated may be rapidly cooled by a cooling medium.

Since the shrink fitting and the quenching are performed simultaneously by the above-described steps, there is no need to quench the outer peripheral surface of the cam lobe in advance. Therefore, there is no problem that tempering occurs during shrink fitting.

Further, since the shrink fitting and the quenching are performed at the same time, there is an additional effect that the number of steps is reduced and the manufacturing efficiency is increased. Furthermore, since it is not necessary to perform heating separately for quenching and shrink fitting, heating is only required once, so that the energy saving effect is high and the heat energy released into the air is small, which is preferable in the global environment.

Further, as set forth in claim 2, the shrink fitting temperature may be lower than the quenching temperature. Even if the shrink fitting temperature is set to a temperature equal to the quenching temperature, both the hardening of the cam lobe outer circumferential surface and the shrink fitting of the cam lobe inner circumferential surface are possible, but the shrink fitting temperature and the quenching temperature are equivalent. Then, the temperature reduction rate due to the insertion of the shaft at the time of shrink fitting or the subsequent cooling becomes slow on the outer peripheral surface side of the cam lobe. For this reason, quenching of the cam lobe outer peripheral surface may become sweet. For this reason, the shrink fitting temperature is preferably lower than the quenching temperature in order to prevent quenching from becoming sweet. Further, even if the shrink fitting temperature is within the temperature range in which shrink fitting is possible, it is better to set the shrink fitting temperature to a range sufficiently lower than the quenching temperature for hardening of the cam lobe outer peripheral surface for the above-described reason. Is preferred for

In the heating step, for example, the outer peripheral surface of the cam lobe is heated to the quenching temperature by heating from the outer peripheral surface side of the cam lobe, and the shaft of the cam lob is inserted into the shaft fitting hole. The inner peripheral surface can be heated to the shrink fitting temperature.

That is, by heating from the outer peripheral surface of the cam lobe, when the outer peripheral surface is heated to the quenching temperature, the inner peripheral surface of the shaft fitting hole can be made lower than the quenching temperature. Since the shrink fitting temperature includes a temperature range lower than the quenching temperature, by adjusting the heating rate of the outer circumferential surface of the cam lobe by heating, the outer circumferential surface of the cam lobe reaches the quenching temperature, The temperature of the inner peripheral surface of the fitting hole can reach the shrink fitting temperature. By heating the outer peripheral surface from the outer peripheral surface at an appropriate heating rate in this manner, the outer peripheral surface of the cam lobe can be easily set to the quenching temperature and the inner peripheral surface of the shaft insertion hole of the cam lobe can be set to the hardening temperature.

Further, as described in claim 4, the heating is performed by, for example, induction heating, thereby realizing heating from the outer peripheral surface of the cam lobe. Therefore, for example, when performing high-frequency heating as one of the induction heating, by adjusting the high-frequency, the heating power, and the heating time, the outer peripheral surface of the cam lobe is brought to the quenching temperature, and at the same time, the inside of the shaft insertion hole of the cam lobe is adjusted. The peripheral surface can be set to the shrink fitting temperature.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a camshaft, the method comprising manufacturing a camshaft by assembling a shaft into a shaft fitting hole of a camrob whose outer peripheral surface is hardened by hardening. A temperature adjusting step of adjusting the temperature to a temperature, a positioning step of positioning the cam lobe, the temperature of which has been adjusted in the temperature adjusting step, while maintaining the shrink-fitting temperature by a temperature adjusting means, A step of fitting a shaft into a shaft fitting hole of the cam lobe, and a cooling step of cooling the cam lobe and the shaft integrated in the fitting step.

In the present camshaft manufacturing method, before the fitting step, a positioning step of positioning the cam lobe whose temperature has been adjusted in the temperature adjusting step while maintaining the shrink fitting temperature by the temperature adjusting means is executed. In this positioning step, if the shrink-fitting temperature is not maintained by the temperature adjusting means, that is, if shrink-fitting is performed as in the prior art, in the temperature adjustment step performed immediately before, in the cam lob positioning step, In consideration of cooling, it is necessary to heat to a temperature considerably higher than the shrink fitting temperature. If the temperature is higher than the shrink fitting temperature in this way, tempering occurs and the hardness of the outer peripheral surface of the cam lobe decreases.

However, according to the present camshaft manufacturing method, the temperature of the cam lobe can be maintained at the shrink fitting temperature by the temperature adjusting means even in the positioning step. Only, and no extra heating is required. Therefore, the outer peripheral surface of the cam lobe is not tempered and does not adversely affect quenching.

Further, since the temperature of the cam lobe can be maintained at the shrink-fitting temperature by the temperature adjusting means in the positioning step, the temperature control of the cam lobe is easy, and the cooling speed of the cam lobe in the positioning step is not considered. This eliminates the need for such a step, so that there is a margin in the execution timing of the fitting step, and a secondary effect that yield is improved by stable work is produced.

Further, in the temperature adjusting step, the heating furnace for heating the cam lobe can be kept at a lower temperature than in the conventional case, and the total amount of energy consumed by the temperature adjusting means can be increased. Requires less energy.
Therefore, since the energy saving effect is high and the heat energy released into the air is small, it is preferable in the global environment.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a camshaft, the method comprising manufacturing a camshaft by assembling a shaft into a shaft fitting hole of a camrob whose outer peripheral surface is hardened by shrink fitting. A temperature adjusting step of adjusting the temperature of the cam lobe positioned in the positioning step to a shrink fitting temperature by a temperature adjusting means; and adjusting the temperature of the cam lobe temperature adjusted to the shrink fitting temperature in the temperature adjusting step. A fitting step of fitting the shaft into the shaft fitting hole and a cooling step of cooling the cam lobe and the shaft integrated in the fitting step are performed.

In this camshaft manufacturing method, the cam lobe is heated to the shrink fitting temperature after the positioning step. Thereafter, the positioned cam lobe is maintained at the shrink fitting temperature. Therefore, the same function and effect as those described in claim 5 are obtained.

According to a seventh aspect of the present invention, as the cooling step, a step of separating the temperature adjusting means from the cam lobe in which the shaft is inserted into the shaft insertion hole in the inserting step is performed, so that the temperature adjusting means is provided. While receiving no heat, the air flows around the cam lobe and the cam lobe and the shaft are rapidly cooled, so that a firmly integrated camshaft can be quickly manufactured.

The method of manufacturing a camshaft according to claim 8 is a method of manufacturing a camshaft by assembling one shaft into each shaft insertion hole of a plurality of cam lobes whose outer peripheral surfaces are hardened by shrink fitting. A temperature adjusting step of adjusting the temperature of each of the cam lobes to substantially the shrink-fitting temperature, and positioning all the cam lobes temperature-adjusted in the temperature adjusting step in a row while maintaining the shrink-fitting temperature by the temperature adjusting means. And a fitting step of fitting one shaft into the shaft fitting holes of all the cam lobes positioned in the positioning step at the same time; and the shaft fitted in the shaft fitting hole in the fitting step. A cooling step for simultaneously separating all the cam lobes and the temperature adjusting means is performed.

This method of manufacturing a camshaft is described in claim 5.
The difference between the configurations 6 and 7 is that a plurality of cam lobes are simultaneously fitted into one shaft. Therefore, the following operation and effect are produced in addition to the operation and effect described in the fifth, sixth, and seventh aspects.

That is, as in the prior art, when the temperature adjusting means is not used, a plurality of cam lobes are arranged in a line,
When fitting a shaft into the shaft fitting hole,
The cooling state of each cam lobe differs depending on the positioning order and the positioning positions of the cam lobes. For this reason, even if the shafts are simultaneously fitted into all the cam lobes, the temperature condition differs for each cam lobe. That is, since the temperature differs for each cam lobe fitted, the amount of heat received from the cam lobe also varies depending on the position of the shaft. For this reason, the thermal expansion of the shaft may differ depending on the position, and the mounting accuracy of the cam lobe in the axial direction may be reduced.

However, since the present camshaft manufacturing method uses the temperature adjusting means, the temperature of the cam lobe is maintained at the same level as the shrink fitting temperature when the shaft is fitted, regardless of the positioning order and the positioning position of the cam lobe. Have been. For this reason, the thermal expansion of the shaft does not differ depending on the position, and the mounting accuracy of the cam lobe in the axial direction does not decrease.

Further, since a plurality of cam lobes can be simultaneously attached to the shaft, productivity can be improved and low cost can be realized, and the relative position between the cam lobes can be accurately set. The mounting accuracy is also improved.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a camshaft by assembling one shaft into each shaft insertion hole of a plurality of cam lobes whose outer peripheral surfaces are hardened by shrink fitting. A positioning step of positioning all the cam lobes in a line, and all of the cam lobes positioned in the positioning step,
A temperature adjusting step of adjusting the temperature to the shrink fitting temperature by the temperature adjusting means, and one shaft is simultaneously fitted into the shaft fitting holes of all the cam lobes whose temperature has been adjusted to the shrink fitting temperature in the temperature adjusting step. A fitting step and a cooling step of simultaneously separating all the cam lobes whose shafts are fitted into the shaft fitting holes in the fitting step and the temperature adjusting means are performed.

In this camshaft manufacturing method, all the cam lobes are heated to the shrink fitting temperature after the positioning step. Thereafter, all the cam lobes positioned are maintained at the shrink fitting temperature. Therefore,
The same operation and effect as described in the eighth aspect are obtained.

According to the tenth aspect, when a three-dimensional cam lobe is used as the cam lobe, especially when a plurality of cam lobes are shrink-fitted at once as in the eighth and ninth aspects, the axial direction of the cam lobe is reduced for the above-described reason. A three-dimensional camshaft with high mounting position accuracy can be manufactured. From this, it is possible to realize high precision especially in the adjustment of the lift amount by adjusting the position of the three-dimensional cam in the axial direction.

The cam lob positioning jig according to the present invention is a positioning jig for positioning the cam lobe at a shaft fitting position when a cam shaft is manufactured by assembling a shaft into a shaft fitting hole of the cam lobe by shrink fitting. Temperature adjusting means for maintaining the temperature of the cam lobe positioned at the shaft fitting position at the shrink fitting temperature.

In the positioning step of the above-described camshaft manufacturing method, by using such a cam lobe positioning jig, the cam lobe whose temperature has been adjusted in the temperature adjusting step can be held in a state where the shrink fitting temperature is maintained by the temperature adjusting means. Positioning can be performed, and the above-described effects can be obtained.

When the above-described camshaft manufacturing method is realized as a camshaft manufacturing apparatus, for example, the following configuration is used. That is, according to the first aspect of the present invention, there is provided an apparatus for manufacturing a camshaft by assembling a shaft into a shaft insertion hole of a cam lobe by shrink fitting, as described in claim 12, wherein the cam lobe is located at a shaft insertion position. Positioning means for positioning;
A heating means for heating the cam lobe positioned by the positioning means; and a heating process performed by the heating means, wherein an outer peripheral surface of the cam lobe is set to a quenching temperature, and an inner peripheral surface of a shaft fitting hole of the cam lobe is shrink-fitted. Heating control means for controlling the temperature to be attained; and shaft fitting means for fitting a shaft into a shaft fitting hole of the cam lobe which is positioned by the positioning means and heated by the heating means controlled by the heating control means. And a camshaft manufacturing apparatus characterized by comprising:

According to the second aspect of the present invention, as described in the thirteenth aspect, in the twelfth aspect,
Since the shrink fitting temperature is lower than the quenching temperature, the camshaft manufacturing apparatus can be configured.

According to a third aspect of the present invention, as described in the fourteenth aspect, in the twelfth aspect or the thirteenth aspect, the camshaft is heated by using the heating means which is heated from the outer peripheral surface side of the cam lobe. It can be configured as a manufacturing device.

According to a fourth aspect of the present invention, as described in the fifteenth aspect, in the fourteenth aspect,
By using an induction heating device as the heating means, a camshaft manufacturing device can be configured.

According to a fifth aspect of the present invention, as described in the sixteenth aspect, an apparatus for manufacturing a camshaft by assembling a shaft into a shaft insertion hole of a cam lobe whose outer peripheral surface is hardened by shrink fitting. Positioning means for positioning the cam lobe at the shaft fitting position; temperature adjusting means for maintaining the temperature of the cam lobe positioned at the shaft fitting position at the shaft fitting position at the shrink fitting temperature; and positioning at the positioning step. ,
A camshaft manufacturing apparatus comprising: a shaft fitting means for fitting a shaft into a shaft fitting hole of the cam lobe maintained at the shrink fitting temperature by the temperature adjusting means.

According to a seventh aspect of the present invention, as shown in the seventeenth aspect, the shaft is fitted into the shaft fitting hole by the shaft fitting means with respect to the configuration of the camshaft manufacturing apparatus according to the sixteenth aspect. In addition, a camshaft manufacturing apparatus can be configured in which a cooling unit for separating the cam lobe and the temperature adjusting unit is added.

According to the eighth and ninth aspects of the present invention, as described in the eighteenth aspect, one shaft is assembled into each of the plurality of cam lobes whose outer peripheral surfaces are hardened by shrink fitting. An apparatus for manufacturing a camshaft, comprising: positioning means for positioning all cam lobes in a line at a shaft insertion position; and maintaining the temperature of all the cam lobes positioned at the shaft insertion position by the positioning means at a shrink-fitting temperature. Temperature adjusting means;
Shaft fitting means for simultaneously fitting one shaft into the shaft fitting holes of all the cam lobes which are positioned in the positioning step and maintained at the shrink fitting temperature by the temperature adjusting means; and the shaft fitting means. And a cooling means for simultaneously separating all of the cam lobes whose shafts are fitted into the shaft fitting holes and the temperature adjusting means.

Further, when the cam lobe is a three-dimensional cam lobe, that is, when the object to be manufactured by the camshaft manufacturing apparatus is a three-dimensional camshaft,
A camshaft manufacturing apparatus that produces the same effects as the tenth aspect can be provided.

[0044]

[First Embodiment] FIG. 1 is a plan view of a three-dimensional cam lobe 11 assembled to a three-dimensional cam shaft manufactured in a first embodiment, and FIG. FIG. 3 is a vertical sectional view of the three-dimensional cam lobe 11, FIG. 4 is a partial perspective view of a three-dimensional cam shaft to which the three-dimensional cam lobe 11 is assembled, and FIG.
FIG. 2 shows a partial perspective view of a state where a three-dimensional camshaft is turned upside down.

The three-dimensional cam lobe 11 has a shaft fitting hole 12 into which the shaft 16 is inserted.
A three-dimensional camshaft is manufactured by fitting and fixing the shaft 16 into the shaft fitting hole 12.

The profile of the three-dimensional cam lobe 11 has the same base circle (base circle), but the height of the cam nose 11a changes continuously along the axis of the three-dimensional cam lobe 11. .

On the end surface of the three-dimensional cam lobe 11 on the high nose side (FIG. 2), three projections 14, 15 having a substantially circular cross section are provided.
Are formed to protrude. The projections 14 and 15 are provided with one projection 14 on the cam nose 11a side and two projections 15 on the opposite side when viewed from the axis of the shaft fitting hole 12. The tip surfaces of the projections 14 and 15 are formed so as to be present on the same plane perpendicular to the axis of the shaft fitting hole 12. The tip surfaces of the projections 14 and 15 serve as reference surfaces for determining the position of the three-dimensional cam lobe 11 and the shaft 16 to which the three-dimensional cam lobe 11 is mounted in the axial direction.

An insertion hole 13 having an axis parallel to the axis of the shaft fitting hole 12 is formed at the center of the projection 14. As will be described later, the insertion hole 13 is inserted with a pin provided on a reference plate on which the three-dimensional cam lobe 11 is mounted at the time of assembly, and is held so that the three-dimensional cam lobe 11 does not rotate around its axis. Used to

Further, the three-dimensional cam lobe 11 is integrally formed with the projections 14 and 15, the shaft fitting hole 12 and the insertion hole 13 by a die working such as powder metallurgy or cold forging. For example, three-dimensional cam lobe 11 by powder metallurgy
Is manufactured by enclosing a metal powder (including a case where a powder of a nonmetallic material is mixed) in a mold obtained by shaping the external shape of the three-dimensional cam lobe 11, applying pressure to the metal powder, and applying a pressure to the metal powder. Press into. Thereafter, this is performed by heating and sintering.

Subsequently, the three-dimensional cam lobe 11 is connected to the shaft 1.
6, the three-dimensional camshaft manufacturing device
This will be described with reference to FIG. As shown in FIG. 6C, in the three-dimensional camshaft manufacturing apparatus 10, the three-dimensional cam lobe 11 includes a reference plate 2 provided on a jig base 20.
0a. The upper end surface of the reference plate 20a is finished with high precision and serves as a reference surface for accurately setting the three-dimensional cam lobe 11. The reference plate 20a corresponds to a positioning unit.

The jig base 20 and the reference plate 20a are formed with through holes 21 extending vertically from the upper end surface. In the through hole 21, a ceramic center pin 22 that is not heated by an induction heating device described later is provided. The center pin 22 is urged upward by a spring 23 and can slide up and down on the axis of the through hole 21. The center pin 22
The diameter of the tip of the center pin 22 is substantially the same as the diameter of the shaft fitting hole 12 formed in the three-dimensional cam lobe 11.
The shaft fitting hole 12 is fitted into the tip of
The axis of the three-dimensional cam lobe 11 can be fixed.

Further, on the reference plate 20a, there is provided a phase determining pin 24 also made of ceramics and having a substantially circular cross section. The diameter of the phase determining pin 24 is determined by the insertion hole 13 provided in the three-dimensional cam lobe 11 for determining the mounting phase.
It is almost the same diameter as. The axis of the phase determining pin 24 is
It is perpendicular to the upper end surface of the reference plate 20a. Further, the distance between the axis of the phase determining pin 24 and the axis of the center pin 22 matches the distance between the axis of the shaft fitting hole 12 of the three-dimensional cam lobe 11 and the axis of the insertion hole 13 for assembling phase. It is formed as follows.

Therefore, the three-dimensional cam lobe 1 for the jig base 20 is fixed by fitting the shaft fitting hole 12 for fitting the shaft into the center pin 22 and further fitting the fixing hole 13 for fitting phase into the phase determining pin 24.
The position of the shaft center of one shaft fitting hole 12 and the assembling phase of the three-dimensional cam lobe 11 can be determined.
Also, a protrusion 1 protruding from the three-dimensional cam lobe 11
By contacting the tip surfaces of the four and 15 with the upper end surface of the reference plate 20a, the position of the three-dimensional cam lobe 11 in the vertical direction with respect to the upper end surface is determined. Further, the axis of the shaft fitting hole 12 is aligned with the upper end surface of the reference plate 20a. Can be accurately arranged to be perpendicular to the reference plane.

Further, two clampers 25 are provided above the reference plate 20a. This is 3D Cam Rob 1
By pressing 1 from above, the vertical movement of the three-dimensional cam lobe 11 is restricted. The clamper 25 is controlled by a power unit (not shown) of an electric type, a hydraulic type, a pneumatic type, or the like so that it can be moved in the horizontal and vertical directions within an allowable range.

On the other hand, as shown in FIGS.
The shaft 16 is attached to a chuck 19. The axial center of the shaft 16 is positioned vertically by the chuck 19. Also, the chuck 1 of the shaft 16
9 is fitted in the fitting hole 1 in a manner shown in FIG.
7 are formed. In the fitting hole 17, the chuck 1
The relative rotation between the shaft 16 and the chuck 19 is restricted by fitting a pin 18 provided on the shaft 9.

Further, the rotation angle and the movement in the vertical direction of the chuck 19 can be automatically controlled while the axis of the shaft 16 is held vertically by a numerical controller (not shown). The chuck 19 and its moving mechanism correspond to shaft fitting means.

In addition to the components described above, the three-dimensional camshaft manufacturing apparatus 10 is provided with an induction heating device including a high-frequency coil 26 for heating the three-dimensional cam lobe 11 and a high-frequency power supply 29. A high frequency power supply 29 is provided around the three-dimensional cam lobe 11 placed on the reference plate 20a.
-Frequency coil 26 that generates a magnetic field under driving by
Is installed so as to be movable in the vertical direction. The high-frequency coil 26 is arranged around the three-dimensional cam lobe 11 during heating, and can be kept on standby so as not to be obstructed when unnecessary.

A high frequency power supply 29 is connected to the high frequency coil 26.
By supplying a higher frequency current, a secondary current is induced in the three-dimensional cam lobe 11, and the self-heating causes the three-dimensional cam lobe 11 to be heated from the outer peripheral surface 11b side. The high-frequency coil 26 and the high-frequency power supply 2
9 corresponds to a heating means.

The three-dimensional camshaft manufacturing apparatus 10
Is provided with a temperature sensor 27 such as a thermocouple or a radiation thermometer for measuring the temperature of the three-dimensional cam lobe 11. During heating, the temperature of the three-dimensional cam lobe 11 is measured by the temperature sensor 27. The temperature control device 28 controls the three-dimensional cam lobe 1 based on the temperature measured by the temperature sensor 27.
The output of the high-frequency power supply 29 is feedback-controlled so that the temperature of 1 becomes a desired temperature. This temperature control device 28 corresponds to a heating control unit.

Here, the temperature control of the three-dimensional cam lobe 11 by the temperature control device 28 is intended to temporarily realize the state shown in FIG. 7 when the shaft 16 is fitted. That is, the temperature control device 28 controls the three-dimensional cam lobe 1
The temperature So of the outer peripheral surface 11b of 1 becomes the quenching temperature and 3
The temperature is controlled to a temperature gradient state in which the temperature Si of the surface (that is, the inner peripheral surface 11c) of the shaft fitting hole 12 of the three-dimensional cam lobe 11 becomes the shrink fitting temperature.

This temperature gradient state only needs to be temporarily realized when the shaft 16 is inserted.
Is achieved by adjusting the rate of temperature rise of the outer peripheral surface 11b of the three-dimensional cam lobe 11. That is, the temperature control device 28
Measures the temperature So of the outer peripheral surface 11b of the three-dimensional cam lobe 11 by the temperature sensor 27, and determines the temperature rise rate of the outer peripheral surface until the temperature So reaches the quenching temperature from room temperature. The frequency is adjusted according to one or both of the frequency and the power output.

If the temperature rise rate of the outer peripheral surface is too slow,
When the temperature So of b reaches the quenching temperature from room temperature, the temperature Si of the inner peripheral surface 11c has already become equal to the quenching temperature as the shrink fitting temperature, and the energy loss is large. Further, when the shrink fitting temperature is equal to the quenching temperature, heat transfer from the inner peripheral surface 11c side increases, and the cooling speed of the outer peripheral surface 11b decreases, so that quenching may be weak. There is.

If the temperature rise rate of the outer peripheral surface is too high, when the temperature So of the outer peripheral surface 11b reaches the quenching temperature from room temperature, the temperature Si of the inner peripheral surface 11c has not yet reached the shrink fitting temperature. It may not be possible to shrink fit immediately. When the temperature Si of the inner peripheral surface 11c is waiting for the shrink fitting temperature to reach, the temperature So of the outer peripheral surface 11b exceeds the quenching temperature region suitable for the quenching temperature, and the outer peripheral surface of the three-dimensional cam lobe 11 There is a possibility that a problem such as thermal deformation of 11b may occur.

Therefore, an appropriate temperature rise rate of the outer peripheral surface 11b at which the temperature gradient state shown in FIG. 7 is realized is measured experimentally in advance in accordance with the material of the three-dimensional cam lobe 11, and is obtained by this measurement. Temperature control device 28
Set to. Thereby, the temperature control device 28 controls one or both of the frequency and the power output from the high-frequency power supply 29 to the high-frequency coil 26 so that the heating rate becomes the set speed based on the temperature detected by the temperature sensor 27. Adjust both.

For example, the material of the three-dimensional cam lobe 11 is an iron-based low alloy sintered material (Fe-0.6Mo-0.5Mn-1.5).
In the case of C), the frequency is 200 kHz and the power is 10.7 kV
By heating at × 5.6A, simultaneously after 5 seconds,
The temperature So of the outer peripheral surface 11b becomes the quenching temperature and the inner peripheral surface 1
The temperature Si of 1c can be set to the shrink fitting temperature.

The outer peripheral surface 11 of the three-dimensional cam lobe 11
When the temperature control device 28 estimates or determines by temperature measurement that the temperature So of the b has reached the quenching temperature and the temperature Si of the inner peripheral surface 11c has reached the shrink fitting temperature, the temperature control device 2
The signal from 8 informs the numerical controller of the insertion timing.

The above-described three-dimensional camshaft manufacturing apparatus 10
FIG. 8 shows a method for manufacturing a three-dimensional camshaft using
This will be described with reference to FIG. First, as shown in FIG. 8, the three-dimensional cam lobe 11 is placed on the reference plate 20a such that the surface on which the protrusions 14 and 15 are present faces down. At this time,
Center pin 22 and phase determination pin 24
The two-dimensional cam lobe 11 is attached so as to be fitted into a shaft fitting hole 12 and a through hole 13 provided in the cam lobe 11. afterwards,
The clamper 25 is moved so as to contact the upper end surface of the three-dimensional cam lobe 11. As a result, the three-dimensional cam lobe 11
In the horizontal and vertical directions and rotation about the axis of the insertion hole 13 are restricted.

On the other hand, the shaft 16 is inserted into the fitting hole 17 and the pin 1.
8 is attached to the chuck 19 in such a manner as to be aligned with 8.
At this time, the axis of the center pin 22 and the axis of the shaft 16 coincide with each other above the jig base 20. The position of the shaft 16 at this time is hereinafter referred to as a shaft standby position for convenience.

After that, the high-frequency coil 26 is moved around the three-dimensional cam lobe 11. Then, a high-frequency current output from the high-frequency power supply 29 is supplied to the high-frequency coil 26.
When a high-frequency current is supplied to the high-frequency coil 26, a secondary current is induced on the outer peripheral surface 11b side of the three-dimensional cam lobe 11 facing the high-frequency coil 26, and the three-dimensional cam lobe 11 is moved by the self-heating. Heated from the 11b side. As a result, a heating step is performed.

The heating rate in this heating step is:
As described above, at the same time, the temperature So of the outer peripheral surface 11b of the three-dimensional cam lobe 11 becomes the quenching temperature, and
It is controlled so that the temperature Si of 1c is the shrink fitting temperature.

At the same time, when the temperature So of the outer peripheral surface 11b of the three-dimensional cam lobe 11 becomes the quenching temperature and the temperature Si of the inner peripheral surface 11c becomes the shrink fitting temperature, the three-dimensional cam lobe 11 thermally expands accordingly, Fitting hole 12
Is also enlarged to the size required for shrink fitting.

When the three-dimensional cam lobe 11 reaches this state, in response to a signal indicating completion of temperature rise from the temperature control device 28,
As shown in FIG. 9, the numerical controller is driven to drive the shaft 1
6 is moved vertically downward, and the shaft 16 is fitted into the shaft fitting hole 12. As a result, the fitting step is performed.

When the shaft 16 is inserted to the required depth, the temperature controller 28 stops supplying the high-frequency current to the high-frequency coil 26 and stops heating the three-dimensional cam lobe 11 according to an instruction from the numerical controller. Further, the three-dimensional cam lobe 11 and the shaft 16 integrated with the cooling medium are rapidly cooled as a whole. As a result, the temperature S of the outer peripheral surface 11b of the three-dimensional cam lobe 11 is increased by the heat absorbing action from the shaft 16 side, the ambient temperature, and the action of the cooling medium.
o rapidly decreases from the quenching temperature, the outer peripheral surface 11b side of the three-dimensional cam lobe 11 is quenched, and the hardness increases. Further, the temperature Si of the inner peripheral surface 11c decreases from the shrink fitting temperature, the inner diameter of the shaft fitting hole 12 is reduced, and the three-dimensional cam lobe 11 and the shaft 16 are firmly fastened by shrink fitting.

When the fastening of the three-dimensional cam lobe 11 and the shaft 16 is completed, as shown in FIG. 10, the clamper 25 is moved upward to release the constraint on the three-dimensional cam lobe 11 from moving upward. Then, the shaft 16 is moved to the shaft standby position by the numerical controller. At this time, since the three-dimensional cam lobe 11 is fastened to the shaft 16, it moves integrally with the shaft 16 as shown in FIG.

The center pin 22 is
Is returned to the original position by the urging force of. Further, the high frequency coil 26 is moved downward. Thus, the assembling work of one three-dimensional cam lobe 11 is completed. Thereafter, as shown in FIG. 11C, a new three-dimensional cam lobe 11 'is placed and positioned on the reference plate 20a in the same manner as before, and as shown in FIG. As a result, the shaft 16 is rotated to an angle that matches the mounting phase of the three-dimensional cam lobe 11 ′. Incidentally, when the camshaft is mounted on a four-cylinder internal combustion engine, and four three-dimensional cam lobes 11 are assembled at an equal phase (angle) of 90 °, an angle matching this assembly phase is used. 90 ° is chosen. Then, as described above, the three-dimensional cam lobe 11 ′ is heated by the high-frequency coil 26. Thereafter, the shaft 16 whose angle has been precisely adjusted is accurately moved vertically downward to the position where the second three-dimensional cam lobe 11 'is assembled, and is inserted into the shaft insertion hole 12' of the three-dimensional cam lobe 11 '. , This second 3
The three-dimensional cam lobe 11 'is shrink-fitted to the shaft 16, and at the same time, the outer peripheral surface 11b' of the three-dimensional cam lobe 11 'is hardened.

Thereafter, the above-described steps are repeated by the required number of the three-dimensional cam lobes 11 to be assembled to the shaft 16, thereby completing the three-dimensional cam shaft. The effects obtained by the above-described embodiment will be described below.

In the present embodiment, as the heating step, the outer peripheral surface 11b of the three-dimensional cam lobe 11 is heated to the quenching temperature and the inner peripheral surface 11c of the three-dimensional cam lobe 11 is heated to the shrink fitting temperature. Since the shrink fitting temperature is lower than the quenching temperature, for example, the outer peripheral surface 11 of the three-dimensional cam lobe 11
b, the outer peripheral surface 11b is brought to the quenching temperature by heating in such a manner that the temperature can be raised from the outer peripheral surface 11b to the inner peripheral surface 11c.
The temperature of the inner peripheral surface 11c existing inside the three-dimensional cam lobe 11 can be naturally adjusted to the shrink fitting temperature by the heat conduction to the inside.

In this state, the fitting step is performed, and the shaft fitting hole 1 of the three-dimensional cam lobe 11 heated to the shrink fitting temperature.
When the shaft 16 is fitted into the shaft 2, the shaft 16 transfers the heat of the three-dimensional cam lobe 11 to the inner peripheral surface 11 c of the shaft fitting hole 12.
Absorbing from the side, the temperature of the three-dimensional cam lobe 11 rapidly decreases and the temperature of the shaft 16 increases. As a result, the three-dimensional cam lobe 11 and the shaft 16 are shrink-fitted and integrated. Further, the outer peripheral surface 11b of the three-dimensional cam lobe 11 is also rapidly deprived of heat from the shaft fitting hole 12 side by heat conduction, and the temperature rapidly decreases from the quenching temperature. As a result, the outer peripheral surface 11b of the three-dimensional cam lobe 11 is hardened. Therefore, since the shrink fitting and the quenching are performed at the same time, it is not necessary to quench the outer peripheral surface 11b of the three-dimensional cam lobe 11 in advance, and it is not necessary to perform tempering as in the related art.

In addition, since the shrink fitting and the quenching can be performed at the same time, the number of steps is reduced and the manufacturing efficiency is increased. Furthermore, since it is not necessary to perform heating separately for quenching and shrink fitting, heating can be performed only once, so that the energy saving effect is high and the heat energy released into the air is small, which is preferable in the global environment.

As shown in FIG. 7, the shrink fitting temperature on the inner peripheral surface 11c of the three-dimensional cam lobe 11 is
It is set sufficiently lower than the quenching temperature on the b side. Therefore, the amount of heat received by the outer peripheral surface 11b side from the inner peripheral surface 11c side is relatively small, and the outer peripheral surface 11b side is rapidly cooled during cooling. Therefore, it is possible to sufficiently prevent the quenching from becoming sweet.

In the heating step, the outer peripheral surface 11b of the three-dimensional cam lobe 11 is heated to the quenching temperature by heating from the outer peripheral surface 11b side of the three-dimensional cam lobe 11, and the inner peripheral surface of the three-dimensional cam lobe 11 is heated. 11c can be heated to the shrink fit temperature. That is, by heating from the outer peripheral surface 11b side of the three-dimensional cam lobe 11, the outer peripheral surface 1b is heated.
1b is raised to the quenching temperature, the inner peripheral surface 11c
Can be lower than the quenching temperature. And
Since the shrink fitting temperature includes a temperature range lower than the quenching temperature, the outer peripheral surface 11 of the three-dimensional cam lobe 11 is heated.
By adjusting the heating rate of b, the three-dimensional cam lobe 1
The temperature of the inner peripheral surface 11c can reach the shrink fitting temperature at the same time as the outer peripheral surface 11b reaches the quenching temperature. By heating the outer peripheral surface 11b at an appropriate heating rate in this manner, the outer peripheral surface 11 of the three-dimensional cam lobe 11 can be easily formed.
b to the quenching temperature, the inner peripheral surface 11 of the three-dimensional cam lobe 11
c can be the shrink fitting temperature.

The heating of the three-dimensional cam lobe 11 is performed by high-frequency heating which is one of induction heating.
Heating from the outer peripheral surface 11b of the three-dimensional cam lobe 11 can be realized. Therefore, by adjusting the frequency, power, and time of the high frequency, the outer peripheral surface 11b of the three-dimensional cam lobe 11 is set to the quenching temperature, and
1 can be set to the shrink fitting temperature.
Further, since the three-dimensional cam lobe 11 itself is internally heated by the induction heating, it is possible to uniformly heat the entire outer peripheral surface 11b of the three-dimensional cam lobe 11. In addition, 3
The deformation of the three-dimensional cam lobe 11 due to thermal expansion can be accurately controlled, and the effect of heat on other components of the three-dimensional camshaft manufacturing apparatus 10 can be suitably avoided.

[Second Embodiment] FIG. 12A is a plan view of a three-dimensional cam lobe 111 assembled to a three-dimensional camshaft manufactured in a second embodiment, and FIG. 12B is a longitudinal sectional view thereof. FIG. 13 shows a partial perspective view of the three-dimensional camshaft 110. FIG.

As shown in these figures, the three-dimensional cam lobe 111 is formed with a shaft fitting hole 113 into which the shaft 114 is fitted. The three-dimensional camshaft 110 is manufactured by fitting and fixing the shaft 114 in the shaft fitting hole 113.

Here, the profile of the three-dimensional cam lobe 111 has a basic circle (base circle) shown in FIG.
Are the same from the upper end surface 111a to the lower end surface 111c, but the height of the nose 111d is different from that of the shaft fitting hole 113.
Changes continuously along the axis of. However, FIG.
In the section from (a) of the upper end face 111a to the middle position 111b, the height of the nose 111d is continuously increased, but in the section from the middle position 111b to the lower end face 111c, the height of the nose 111d is the same. ing. Therefore, in the section from the intermediate position 111b to the lower end surface 111c, the profile does not change at all, and the profile surface is a substantially elliptic cylindrical surface extending parallel to the axis of the shaft fitting hole 113. Hereafter, this section is referred to as the parallel part 1
It will be referred to as 12.

The three-dimensional cam lobe 111 is manufactured by a molding process such as powder metallurgy or cold forging in the same manner as in the first embodiment, and the shape of the cam profile including the parallel portion 112 is the same. Finished with extremely high precision. However, unlike the first embodiment, a three-dimensional cam lobe 111 used in the present embodiment is one that has already been hardened on the outer peripheral surface 111e side. The three-dimensional cam lobe 111 may be obtained by hardening the entire three-dimensional cam lobe 111 by a normal hardening process.

On the other hand, when assembling the three-dimensional cam lobe 111 to the shaft 114, as shown in FIG.
Using three cam lobe positioning jigs 115 and 116, the axis of the three-dimensional cam lobe 111 and the assembly phase are fixed. These cam lobe positioning jigs 115, 116
Is made of a plate material having a rectangular cross section having V-shaped grooves 117 and 118 formed at a tip thereof in a substantially V shape when viewed from above. The end surfaces (reference surfaces) of these V-shaped grooves 117 and 118 are planes parallel to the axis of the fixed three-dimensional cam lobe 111.

The cam lobe positioning jig 115,
116, the three-dimensional cam lobe 111
It is sandwiched from the d side and the opposite side. Thus, the three-dimensional cam lobe 111 and the cam lobe positioning jigs 115, 11
6 is a line contact as shown in FIGS. 14 (a) and 14 (b). Even with a three-dimensional cam, by fixing the axis of the three-dimensional cam lobe 111 and the assembling phase by line contact in this way, the phase can be easily and accurately determined, and the three-dimensional cam lobe 111 is determined. Of the edge of the cam lobe and the jig 11
5, 116, etc. can be avoided. These cam lobe positioning jigs 115 and 116 and a reference plate 120 described later correspond to a positioning unit.

Next, the cam lobe positioning jigs 115, 11
A method of manufacturing the three-dimensional camshaft 110 for assembling the three-dimensional cam lobe 111 to the shaft 114 using the method 6 and an apparatus therefor will be described.

As shown in FIG. 15C, the three-dimensional cam lobe 111 is placed on the upper end surface of the reference plate 120 provided on the base 119. The base 119 and the reference plate 120 are each formed with a hole 121 having a diameter slightly larger than the shaft 114 from the upper end surface of the base 119 and vertically downward. The hole 121 serves as an escape hole when the shaft 114 is penetrated by the shaft fitting hole 113 of the three-dimensional cam lobe 111.

In the reference plate 120, heaters 120a, 1
20b and a temperature sensor 120c are provided.
0, a power supply is built in and the heaters 120a, 12a
A temperature maintaining circuit 120d for connecting the temperature sensor 120b to the temperature sensor 120c is provided. Temperature maintenance circuit 120d
Detects the temperature in the reference plate 120 by the temperature sensor 120c, and detects the three-dimensional cam lobe 11 placed on the reference plate 120.
1 is maintained at the shrink fit temperature.
a, 120b to control the amount of current flowing through
a, 120b, the amount of generated heat released to the reference plate 120 is adjusted. These reference plate 120, heater 120a,
120b, temperature sensor 120c and temperature maintaining circuit 12
0d corresponds to the temperature adjusting means.

Further, at the same height as the three-dimensional cam lobe 111 when the three-dimensional cam lobe 111 is arranged on the reference plate 120, cam lobe positioning jigs 115 and 116 are movably installed. The cam lobe positioning jigs 115 and 116 are freely controlled to move in the horizontal direction by a drive mechanism (not shown) such as an electric type, a hydraulic type, or a pneumatic type.

Also, the cam lobe positioning jigs 115, 11
Above 6, two clampers 122 are installed. This is to limit the vertical movement of the three-dimensional cam lobe 111 by pressing the three-dimensional cam lobe 111 from above. The movement of the clamper 122 in the horizontal and vertical directions is also freely controlled by a drive mechanism (not shown).

On the other hand, as shown in FIG. 15B, the shaft 114 is attached to the chuck 123. The chuck 123 lifts the shaft 114 so that the axis A of the shaft 114 is vertical. Further, a pin 124 provided on the chuck 123 is inserted into an insertion hole 126 formed on one end surface of the shaft 114 [FIG.
, Restricts relative rotation of the shaft 114 and the chuck 123 about the axis A.

Further, the moving mechanism of the chuck 123 (not shown) is driven and controlled by a numerical controller (not shown).
4, while the axis A is kept vertical, the position can be freely and accurately adjusted in the axial direction (vertical direction) and the rotation direction.
The chuck 123 and its moving mechanism correspond to a shaft fitting unit.

A procedure for manufacturing a three-dimensional camshaft using the three-dimensional camshaft manufacturing apparatus 109 configured as described above will be described with reference to FIGS. First, the shaft 114 is attached to the chuck 123 as shown in FIG. The chuck 123
Are the distance from the upper end surface of the reference plate 120, the positions of the central axes of the shaft fitting holes 113 and the holes 121, and
Positioning is accurately performed by the numerical controller with reference to the angle 4 and the like. In addition, by instructing the temperature maintenance circuit 120d, when the three-dimensional cam lobe 111 is placed on the reference plate 120, the numerical controller keeps the temperature of the three-dimensional cam lobe 111 at the shrink fitting temperature. The reference plate 120 is previously heated to the shrink-fitting temperature or a temperature slightly higher than the shrink-fitting temperature by the heaters 120a and 120b.

On the other hand, for the three-dimensional cam lobe 111,
Before being placed on the upper end surface of the reference plate 120, as a temperature adjustment step, heating is performed to a shrink fitting temperature in a heating furnace (not shown) such as an electric furnace or a high-frequency heating furnace. Due to the thermal expansion caused by this heating,
The shaft fitting hole 113 of the three-dimensional cam lobe 111 is enlarged to a diameter that allows the shaft 114 to be inserted.

Then, as a positioning step, the heated three-dimensional cam lobe 111 is placed on the reference plate 120 in the mode shown in FIG. At this time, as described above, since the reference plate 120 is heated so that the temperature of the three-dimensional cam lobe 111 is maintained at the shrink fitting temperature, the three-dimensional cam lobe 111 heated to the shrink fitting temperature is moved to the reference plate 120.
Even if it is placed on the top, the three-dimensional cam lobe 111 is not cooled, and maintains a preset shrink fitting temperature.

Then, the cam lobe positioning jigs 115, 1
16 is horizontally moved in a direction approaching the three-dimensional cam lobe 111. The parallel part 112 provided on the profile surface of the three-dimensional cam lobe 111 and the cam lobe positioning jig 11
The end faces (reference planes) of the V-shaped grooves 117 and 118 of the 5 and 116 abut on each other in the manner shown in FIG.
The rotation about the axis 3 is restricted.

Thereafter, the clamper 122 is moved in the horizontal and vertical directions in the manner shown in FIG. 16 so that the lower end surface of the clamper 122 is brought into contact with the upper end surface of the three-dimensional cam lobe 111. By such an operation of the clamper 122, the vertical movement of the three-dimensional cam lobe 111 is also restricted.

By these series of positioning steps, the axis A of the shaft 114 and the axis of the shaft insertion hole 113 can be made coincident, the three-dimensional cam lobe 111 can be fixed to the assembled phase, and the three-dimensional cam lobe 111 can be set to the shrink fitting temperature. Can be maintained.

After this positioning step is completed, as a fitting step, the shaft 114 is moved vertically downward together with the chucks 123 by the numerical controller, and the shaft 114 is inserted into the shaft fitting hole 113 in the manner shown in FIG. At this time, since the diameter of the shaft fitting hole 113 is enlarged by thermal expansion as described above, the shaft 114 is smoothly inserted, and the shaft 114 is accurately inserted to a depth at which the three-dimensional cam lobe 111 is assembled. Is done.

Thereafter, as a cooling step, the temperature maintaining circuit 120d, which has received the fitting end signal from the numerical controller, cuts off the current to the heaters 120a and 120b,
No heat is supplied to the three-dimensional cam lobe 111 from 0, and the three-dimensional cam lobe 111 is cooled by heat radiation until the temperature of the three-dimensional cam lobe 111 becomes equal to or lower than the temperature at which it is determined that shrink fitting is completed. By this cooling, the diameter of the shaft insertion hole 113 is reduced, and the shaft 114 and the three-dimensional cam lobe 111 are maintained in a firmly connected state by so-called shrink fitting.

After the shrink fitting is completed, the cam lobe positioning jigs 115 and 116 and the clamper 122 are moved in a direction to separate from the three-dimensional cam lobe 111 in a manner shown in FIG. . Then, the shaft 114 is moved vertically upward while being fixed to the chuck 123 by the numerical controller. Since the three-dimensional cam lobe 111 is fastened to the shaft 114, it moves integrally with the shaft 114 as shown in FIG.

Thus, the assembling work for one piece of the three-dimensional cam lobe 111 is completed. Thereafter, as shown in FIG. 19, the new three-dimensional cam lobe 111 ′ is heated to the shrink fitting temperature in the same manner as before, and is placed on the reference plate 220 that has been heated so as to maintain the shrink fitting temperature in advance. The shaft 114 is fixed by the cam lobe positioning jigs 115 and 116 and the clamper 122, and the shaft 114 is rotated by the numerical controller to an angle that matches the mounting angle of the three-dimensional cam lobe 111 ′. Incidentally, when the camshaft is mounted on a four-cylinder internal combustion engine and four three-dimensional cam lobes 111 are assembled at an equal phase (angle) of 90 °,
90 ° is selected as an angle that matches this mounting angle. Then, the shaft 114 whose angle has been precisely adjusted is accurately moved vertically downward to the position where the second three-dimensional cam lobe 111 'is assembled, and cooled as described above, whereby the second three-dimensional cam lobe 111' is cooled. Kam Rob 1
11 ′ is shrink-fitted to the shaft 114.

Thereafter, the above-described steps are repeated by the number of three-dimensional cam lobes to be assembled to the shaft 114, whereby the three-dimensional cam shaft 110 is completed. According to the embodiment described above, the following effects can be obtained.

That is, in the production by the three-dimensional camshaft production apparatus 109, before the fitting step of fitting the shaft 114 into the three-dimensional cam lobe 111, the temperature was adjusted to the shrink fitting temperature in the heating furnace in the temperature adjusting step. The three-dimensional cam lobe 111 is connected to the reference plate 120, the heaters 120a, 120
b, the reference plate 120, the cam lobe positioning jigs 115 and 116 while the shrink-fitting temperature is maintained by the temperature adjusting means including the temperature sensor 120c and the temperature maintaining circuit 120d.
Then, a positioning step of positioning by the clamper 122 is executed.

In this positioning step, if the shrink-fitting temperature is not maintained by the temperature adjusting means, that is, shrink-fitting is performed only by the temperature adjusting step of heating the three-dimensional cam lobe 111 with a heating furnace as in the prior art. If
In this temperature adjustment step, it is necessary to heat the three-dimensional cam lobe 111 to a considerably higher temperature than the required shrink fitting temperature in consideration of the cooling in the positioning step. When the temperature is set higher than the required shrink fitting temperature, tempering of the outer peripheral surface 111e of the three-dimensional cam lobe 111 occurs, and the hardness of the outer peripheral surface 111e of the three-dimensional cam lobe 111 that has been hardened is reduced. Would.

However, the present three-dimensional camshaft manufacturing apparatus 1
In the manufacturing method according to No. 09, the temperature of the three-dimensional cam lobe 111 can be maintained at the shrink-fitting temperature by the temperature adjusting means even in the positioning step, so that in the temperature adjusting step immediately before the positioning step, heating to almost the shrink-fitting temperature is sufficient. Often, no extra heating is required. Therefore, three-dimensional cam lobe 1
The outer peripheral surface 111e of 11 is not tempered, and does not adversely affect the quenching that has already been performed.

Further, since the temperature of the three-dimensional cam lobe 111 can be maintained at the shrink-fitting temperature by the temperature adjusting means in the positioning step, the temperature of the three-dimensional cam lobe 111 can be easily controlled, and the three-dimensional cam lobe 111 can be easily controlled in the positioning step. Dimensional cam lobe 1
There is no need to worry about the cooling speed of the eleventh step, so that there is a margin in the execution timing of the fitting step, and there is a secondary effect that the yield is improved by the stable work.

Further, in the temperature adjustment step, the heating furnace for heating the three-dimensional cam lobe 111 can be kept at a lower temperature than in the past, and even if the energy is consumed by the temperature adjustment means, the total Energy consumption is small, the energy saving effect is high, and the heat energy released into the air is small, which is also preferable in the global environment.

[Embodiment 3] In this embodiment, as shown in cross sections in FIGS. 20 and 21, the configuration of the reference plate 220 of the three-dimensional camshaft manufacturing apparatus is the same as that of the reference plate 120 used in the second embodiment. And different. Embodiment 2
The same components as those described above are denoted by the same reference numerals, and detailed description is omitted.

In the reference plate 220, the heater 220
a, 220b and a temperature sensor 220c, and the temperature maintaining circuit 220d maintains the three-dimensional cam lobe mounted on the reference plate 220 at a required shrink fitting temperature based on the temperature detected from the temperature sensor 220c. As described above, the point of adjusting the temperature of the reference plate 220 is described in the second embodiment.
Is the same as the reference plate 120. That is, the reference plate 220, the heaters 220a and 220b, and the temperature sensor 220
c and the temperature maintaining circuit 220d correspond to a temperature adjusting unit.

The difference from the reference plate 120 of the second embodiment is that cam lobe lifting mechanisms 230 and 232 are provided on the mounting surface 220s side of the reference plate 220. The cam lobe lifting mechanisms 230 and 232
The movable pins 230a, 2a are inserted into pin receiving holes 220t, 220u provided in the reference plate 220 so as to open on the 0s side.
32a is provided.

The movable pins 230a and 232a are provided at their sliding ends 230d and 232d with pin receiving holes 220t and 220t, respectively.
By partitioning 220u, the first hydraulic chambers 230b, 232
b and the second hydraulic chambers 230c and 232c.
The movable pins 230a and 232a are connected to the first hydraulic chamber 2
The hydraulic oil is supplied to the second hydraulic chamber 230b.
20C and 232c by discharging the hydraulic oil,
21 changes to the state shown in FIG. 21, and the movable pins 230 a and 232 a protrude toward the mounting surface 220 s of the reference plate 220.

Conversely, the second hydraulic chambers 230c and 232
By supplying hydraulic oil to the first hydraulic chamber 230b and discharging the hydraulic oil from the first hydraulic chambers 230b and 232b, the state shown in FIG. 21 changes to the state shown in FIG.
32a returns into the pin receiving holes 220t and 220u.

Thus, the movable pins 230a, 23
By operating 2a, the three-dimensional cam lobe mounted on the mounting surface 220s is separated from the mounting surface 220s,
It can be in close contact with the mounting surface 220s.

The operation of the movable pins 230a and 232a is adjusted by a hydraulic circuit 236 supplied with high-pressure hydraulic oil from a hydraulic source 234. And this hydraulic circuit 2
The timing of the operation of the movable pins 230a and 232a by 36 is controlled by a signal from the numerical controller that controls the insertion. These cam lobe lifting mechanisms 2
30, 232 and the hydraulic circuit 236 correspond to the cooling means.

The manufacturing procedure of a three-dimensional camshaft using the three-dimensional camshaft manufacturing apparatus 202 configured as described above will be described with reference to FIGS. The cam lobe lifting mechanisms 230 and 232 are
FIG. 22 to FIG. 26 schematically show.

First, the shaft 114 is attached to the chuck 123 as shown in FIG. As in the case of the second embodiment, the chuck 123 is
, Distance from the upper end face, shaft fitting hole 113 and hole 1
The position is accurately determined by the numerical controller with reference to the position of the central axis 21, the angle of the pin 124, and the like.
Further, the numerical controller uses the temperature maintenance circuit 220d to
When the three-dimensional cam lobe 111, which has already been hardened on the outer peripheral surface 111e side, is placed on the reference plate 220,
In order to maintain the temperature of the three-dimensional cam lobe 111 at the shrink fitting temperature, the reference plate 220 is previously heated to a shrink fitting temperature or a temperature slightly higher than the shrink fitting temperature by the heaters 220a and 220b and the temperature sensor 220c.

Further, the cam lobe lifting mechanisms 230 and 23
With respect to 2, the numerical controller controls the hydraulic circuit 236 to supply hydraulic oil to the second hydraulic chambers 230c and 232c and to discharge hydraulic oil from the first hydraulic chambers 230b and 232b, thereby controlling the movable pin. 230a and 232a are completely housed in the pin housing holes 220t and 220u. That is, the state is as shown in FIG.

On the other hand, for the three-dimensional cam lobe 111,
As a temperature adjusting step, the steel sheet is heated to a shrink fitting temperature in a heating furnace such as an electric furnace or a high-frequency heating furnace (not shown). Then, as a positioning step, the heated three-dimensional cam lobe 111
Is mounted on the reference plate 220 in the mode shown in FIG. At this time, as described above, the movable pins 230a,
232a is completely accommodated in the pin accommodating holes 220t and 220u.
0 can be closely attached to the mounting surface 220s. Accordingly, the heat is sufficiently transmitted by the reference plate 220 which is heated so as to maintain the temperature of the three-dimensional cam lobe 111 at the shrink fitting temperature.
1 is placed on the reference plate 220, the three-dimensional cam lobe 11
1 is not cooled and maintains the shrink fit temperature.

Next, the cam lobe positioning jigs 115, 1
16 is horizontally moved in a direction approaching the three-dimensional cam lobe 111. The parallel part 112 provided on the profile surface of the three-dimensional cam lobe 111 and the cam lobe positioning jig 11
23, the end faces (reference planes) of the V-shaped grooves 117 and 118 are brought into contact with each other in the manner shown in FIG.
The rotation about the axis 3 is restricted.

Thereafter, the clamper 122 is moved in the horizontal and vertical directions in the manner shown in FIG. 23, and the lower end surface of the clamper 122 is brought into contact with the upper end surface of the three-dimensional cam lobe 111. By such an operation of the clamper 122, the vertical movement of the three-dimensional cam lobe 111 is also restricted.

By these series of positioning steps, the axis A of the shaft 114 and the axis of the shaft insertion hole 113 can be made coincident, the three-dimensional cam lobe 111 can be assembled and fixed to the phase, and the three-dimensional cam lobe 111 can be set to the shrink fitting temperature. Can be maintained.

After the positioning step is completed, as a fitting step, the shaft 114 is moved vertically downward together with the chucks 123 by the numerical controller, and the shaft 114 is inserted into the shaft fitting hole 113 in a manner shown in FIG. At this time, since the diameter of the shaft fitting hole 113 is enlarged by thermal expansion as described above, the shaft 114 is smoothly inserted, and the shaft 114 is accurately inserted to a depth at which the three-dimensional cam lobe 111 is assembled. Is done.

Thereafter, as a cooling step, the hydraulic circuit 236 receiving the fitting end signal from the numerical controller supplies hydraulic oil to the first hydraulic chambers 230b and 232b and operates from the second hydraulic chambers 230c and 232c. The movable pins 230a and 232a are controlled to discharge oil, and
At t, 220u, it is projected to the mounting surface 220s of the reference plate 220. That is, the state shown in FIG. Further, the hydraulic pins 236a and 232a
At the same time, the numerical control device
The chuck 123, the clamper 122, and the cam lobe positioning jigs 115 and 116 are moved upward by the amount of protrusion of the movable pins 230a and 232a. By this series of cooling steps, as shown in FIG.
Of the reference plate 220 is separated from the mounting surface 220s of the reference plate 220.

As described above, by separating the three-dimensional cam lobe 111 from the mounting surface 220 s of the reference plate 220, which is temperature-controlled for maintaining the temperature, the temperature of the three-dimensional cam lobe 111 is increased by the air existing around. Is deprived and cooled. Due to this cooling, the diameter of the shaft fitting hole 113 of the three-dimensional cam lobe 111 is reduced, and the shaft 114 and the three-dimensional cam lobe 111 are held in a firmly fastened state by shrink fitting.

After the shrink fitting is completed, the numerical controller controls the cam lobe positioning jig 11 in the manner shown in FIG.
5, 116 and the clamper 122 are connected to the three-dimensional cam lobe 11.
The three-dimensional cam lobe 111 is released by moving it in the direction away from 1. Then, the shaft 114 is moved vertically upward while being fixed to the chuck 123 by the numerical controller. The three-dimensional cam lobe 111 is the shaft 11
4 and moves integrally with the shaft 114 as shown in FIG. Further, the hydraulic circuit 236 that has received the fitting end signal from the numerical control device,
The hydraulic oil is supplied to the hydraulic chambers 230c and 232c, and the hydraulic oil is discharged from the first hydraulic chambers 230b and 232b.
0t, 220u. That is, the state is returned to the state shown in FIG.

Thus, the assembling work for one piece of the three-dimensional cam lobe 111 is completed. Thereafter, the new three-dimensional cam lobe is heated to the shrink fitting temperature in the same manner as described above, and the shaft 114 is rotated by the numerical controller to an angle that matches the mounting angle of the new three-dimensional cam lobe. The operation as shown in FIG. 26 is repeated by the number of three-dimensional cam lobes to be assembled to the shaft 114, whereby the three-dimensional cam shaft 110 is completed.

According to the present embodiment described above, the following effects can be obtained in addition to the effects of the second embodiment. That is, by adding a cooling step of separating the three-dimensional cam lobe 111 in which the shaft 114 is fitted into the shaft fitting hole 113 and the reference plate 220 in the fitting step, heat received from the reference plate 220 is not received, and The air flows around the three-dimensional cam lobe 111 to rapidly cool the three-dimensional cam lobe 111 and the shaft 114, so that the three-dimensional camshaft 110 that is firmly integrated can be rapidly manufactured.

[Embodiment 4] In this embodiment, unlike the above-described embodiments, FIGS.
As described above, a three-dimensional camshaft manufacturing apparatus 310 and a three-dimensional camshaft manufacturing method in which all three-dimensional cam lobes 342, 344, 346, and 348 mounted on one shaft 314 are simultaneously fitted and mounted will be described.
27, 30, 31, 32, and 33 show four valves 4
Only a portion related to the first cylinder and the second cylinder in the cylinder engine is shown. (Parts related to the third cylinder and the fourth cylinder are not shown.) In the three-dimensional camshaft manufacturing apparatus 310, the chuck and its moving mechanism are not shown, but are shown in the embodiment. The same configuration as that of the configurations 1 to 3 is used. The chuck and its moving mechanism correspond to shaft fitting means.
The shape of each of the four three-dimensional cam lobes 342 to 348 used in the present embodiment is the same as the shape of the three-dimensional cam lobe 111 used in the second and third embodiments.

From the base 350 of the three-dimensional camshaft manufacturing apparatus 310, a total of eight jig support arms 352, 353, 354, 355, 356, 357,
358, 359 protrude horizontally, and cam lobe positioning jigs 360, 361, 362, 363, 364, 36 are provided at the tips of the jig support arms 352 to 359, respectively.
5,366,367 are attached. Note that FIG.
7, 30, 31, 32, and 33 are described in the vertical section, and therefore, half of the jig support arms 352 and 35
Only 4, 356, 358 and half of the cam lobe positioning jigs 360, 362, 364, 366 are shown. Each of the cam lobe positioning jigs 360 to 367 is a set of two, and the arrangement interval of each set is determined by a plurality of three-dimensional cam lobes 34 attached to the shaft 314.
It corresponds to the arrangement of 2 to 348.

Two sets of cam lobe positioning jigs 360 and 36
As shown in FIG. 28, 1,362 and 363 are longitudinal grooves 360a and 361 on the side faces facing each other for each group.
a, 362a and 363a. This groove 360a
363a are the profiles on the maximum lift side of the three-dimensional cam lobes 342 and 344 at the center when they are brought into close contact with each pair (that is, the profile of the parallel part 112 of the three-dimensional cam lobe 111 used in the second and third embodiments). The cam lobe arrangement holes 368 and 370 having the same shape as those of FIG.

The other two sets of cam lobe positioning jigs 364
As shown in FIG. 29, 365, 366 and 367 are provided with longitudinal grooves 364a and 364 on the side surface facing the other side for each pair.
65a, 366a and 367a. This groove 36
When 4a to 367a are in close contact with each other, cam lobe arrangement holes 372 and 374 having the same shape as the profile on the maximum lift side of the three-dimensional cam lobes 346 and 348 are formed at the center. However, the cam lobe arrangement holes 372 and 374 are
The above two sets of cam lobe positioning jigs 360, 361,
Unlike the cam lobe arrangement holes 368 and 370 of 362 and 363, the three-dimensional cam lobe is arranged in a state where the phases are different by 90 °.

The above-described cam lobe arrangement holes 368, 370,
372 and 374 are three-dimensional cam lobes 342 at the time of shrink fitting.
To 348 are stored, and the rotational phases of the three-dimensional cam lobes 342 to 348 are determined.

Also, a three-dimensional camshaft manufacturing apparatus 310
From the base 350, the eight jig support arms 35
A set of two reference plate support arms 375, 376, 377, 378, 379, 380,
381 and 382 are projected horizontally, and a pair of reference plates 3 is provided at the tips of the reference plate support arms 375 to 382.
83,384,385,386,387,388,38
9,390 are attached. This reference plate 383-
390 is in close contact with the lower surface side for each of the cam lobe positioning jigs 360 to 367, and the respective mounting surfaces 383s, 384s,
385s, 386s, 387s, 388s, 389s,
390 s is a reference plane for determining the vertical position of the three-dimensional cam lobes 342 to 348 arranged in the cam lobe arrangement holes 368 to 374 of the cam lobe positioning jigs 360 to 367. Also, semi-cylindrical grooves 383a, 384a, 385 are provided on the contact surfaces of each set of two reference plates 383-390.
a, 386a, 387a, 388a, 389a, 390
a is provided vertically, and each of the two grooves 383 a to 383 a
0a are combined to form four shaft through holes 392,
394, 396, and 398.

The jig support arms 352 to 359,
The cam lobe positioning jigs 360 to 367, the reference plate support arms 375 to 382, and the reference plates 383 to 390 correspond to positioning means.

As shown in FIG. 27, heat insulators 400, 402, 404, and 406 are provided at the base ends of the jig support arms 352 to 359 attached to the base 350, and the cam lobe positioning jig 360 is provided. 367 to prevent heat from being transmitted to the base 350. Similarly, a heat insulator 4 is also provided at the base end of the reference plate support arms 375-382.
08, 410, 412, 414 are provided, and the reference plate 38 is provided.
The heat is prevented from being transmitted to the base 350 from the 3-390 side. These heat insulators 400 to 414 prevent the base 350 from expanding due to heat at the time of shrink fitting, and in particular, prevent a decrease in the interval accuracy between each set of the reference plate support arms 375 to 382, and This is so as not to affect the mounting position accuracy of the three-dimensional cam lobes 342 to 348.

The swing mechanism 41 is attached to the base ends of the jig support arms 352 to 359 and the reference plate support arms 375 to 382 attached to the base 350, respectively.
6,418,420,422,424,426,42
8,430 are provided. This swing mechanism 416-4
Reference numeral 30 denotes a jig support arm 352-3 only in the horizontal direction as shown by dashed-dotted arrows E and F in FIGS.
59 and the reference plate support arms 375 to 382 can be swung to open. This swing mechanism 416-43
Numeral 0 is constituted by an actuator such as a hydraulic mechanism, a motor or an electromagnetic solenoid, and is driven by an instruction from a numerical controller.

Among the swing mechanisms 416 to 430, the swing mechanisms 424, 426, 428, and 430 provided at the base ends of the reference plate support arms 375 to 382 correspond to cooling means. The swinging mechanisms 424 to 430 open the reference plate support arms 375 to 382 to open the reference plate 383.
To 390 can be retracted from beneath the cam lobe positioning jigs 360 to 367.

The reference plates 383 to 390 have heaters 383b, 384b, 385b, 386b, 3 respectively.
87b, 388b, 389b, 390b (note that heaters 384b, 386b, 388b, 390b are not shown) and temperature sensors 383c, 384c, 385
c, 386c, 387c, 388c, 389c, 390
c (note that the temperature sensors 384c, 386c, 388c,
390c is not shown). The temperature maintaining circuit 440 uses the heaters 383b to 390b and the temperature sensors 383c to 390c to generate the reference plates 383 to 390c.
390 can be heated to the required temperature. These reference plates 383
To 390, heaters 383b to 390b, temperature sensor 38
3c to 390c and the temperature maintaining circuit 440 correspond to a temperature adjusting unit.

A procedure for manufacturing a three-dimensional camshaft using the three-dimensional camshaft manufacturing apparatus 310 thus configured will be described with reference to FIGS. First, the shaft 314 is attached to a chuck (not shown) as in the second and third embodiments. The numerical control device instructs the temperature maintaining circuit 440 in advance to place the three-dimensional cam lobes 342 to 342 on the reference plates 383 to 390.
When the respective 348 are placed, the amounts of heat generated by the heaters 383b to 390b are adjusted based on the detected temperatures of the temperature sensors 383c to 390c so that the temperatures of the three-dimensional cam lobes 342 to 348 can be maintained at the shrink-fitting temperature. Thus, all the reference plates 383 to 390 are heated to the shrink fitting temperature or a temperature slightly higher than the shrink fitting temperature.

The swing mechanisms 416 to 430 are closed as shown in FIGS. 28 and 29 according to instructions from the numerical controller, and the cam lobe arrangement holes 368 to 374 are provided.
When the three-dimensional cam lobes 342 to 348 are inserted into the
Three-dimensional cam lobe 342 in cam lobe arrangement holes 368-374
348 are fitted to determine the rotation phase, and the bottom surfaces 342a, 344a, 344a, 344a, 344b of the three-dimensional cam lobes 342-348 are placed on the mounting surfaces 383s-390s of the reference plates 383-390.
346a and 348a are in contact with each other to perform vertical positioning.

As for the three-dimensional cam lobes 342 to 348 before being inserted into the cam lobe arrangement holes 368 to 374, the three-dimensional cam lobes 34 to 348 are used as a temperature adjustment step.
All of 2 to 348 are heated to a shrink fitting temperature in a heating furnace such as an electric furnace or a high-frequency heating furnace (not shown).

Then, as a positioning step, the heated three-dimensional cam lobes 342 to 348 are inserted into the cam lobe arrangement holes 368 to 374 in the manner shown in FIG.
Thus, as described above, each three-dimensional cam lobe 342
348, and each three-dimensional cam lobe 342
~ 348 shaft fitting holes 342b, 344b, 346
b and 348b are arranged in a line with the same axis. At this time, the three-dimensional cam lobes 342 to 348 are
Since it is in close contact with the mounting surfaces 383s to 390s of the 390,
Heat is sufficiently transmitted by the reference plates 383 to 390 which are heated so as to maintain the temperature of the three-dimensional cam lobes 342 to 348 at the shrink fitting temperature, and the three-dimensional cam lobes 342 to 348 heated to the shrink fitting temperature are inserted into the cam lobe arrangement holes 368. ~ 3
The three-dimensional cam lobes 342 to 348 are not cooled even if they are inserted into the three-dimensional cam lobes 342.
348 are maintained at a suitable shrink fit temperature.

As described above, the four three-dimensional cam lobes 342
After the positioning of to 348 is completed, as a fitting step, the chuck 314 is moved vertically downward together with the chuck by the numerical controller, and as shown in FIG.
Are sequentially inserted into the shaft fitting holes 342b to 348b of the three-dimensional cam lobes 342 to 348. At this time, since the diameters of the shaft fitting holes 342b to 348b are enlarged by thermal expansion as described above, the insertion of the shaft 314 is performed smoothly, and the shaft 314 is inserted into the three-dimensional cam lobe 3.
It is inserted accurately to a depth that is the mounting position of 42 to 348.

By inserting the shaft 314, the three-dimensional cam lobes 342 to 348 are cooled and the three-dimensional cam lobes 342 to 348 are cooled.
The diameters of 42b to 348b are reduced, and the shaft 314
To grip.

Then, as shown in FIG. 32, as a cooling step, the reference plate-side swinging mechanisms 424 to 430 are driven by the instruction of the numerical controller to form a set of two reference plate support arms. 375-382 are simultaneously opened. As a result, the reference plates 383 to 390 are connected to the three-dimensional cam lobe 34.
Separate from the bottom surfaces 342a to 348a of 2 to 348 and the bottom surfaces of the cam lobe positioning jigs 360 to 367. For this reason, the heat of the heaters 383b to 390b is
42-348 and cam lobe positioning jigs 360-36
7, and the three-dimensional cam lobes 342 to 34
8 is rapidly cooled together with the cam lobe positioning jigs 360 to 367. This completes the shrink fit on the shaft 314.

Next, as shown in FIG. 33, the swing mechanism 41 for the cam lobe positioning jig is instructed by the numerical controller.
6 to 422 to drive the jig support arm 3
Each set of 52 to 359 is opened. As a result, the cam lobe positioning jigs 360 to 367 become three-dimensional cam lobes 342 to 342.
Since the restriction of 348 is released, the shaft 314 is moved vertically upward by the numerical controller while the shaft 314 is fixed to the chuck. Since the three-dimensional cam lobes 342 to 348 are fastened to the shaft 314, they move integrally with the shaft 314. Thus, the three-dimensional camshaft 450 is completed.

As described above, the operation of assembling all the three-dimensional cam lobes 342 to 348 to the shaft 314 is completed by one fitting operation. After that, a new multiple 3
If the three-dimensional cam lobe is heated to the shrink-fitting temperature in the same manner as described above, and the operation as shown in FIGS. 30 to 33 is repeated using a new shaft, a new three-dimensional cam shaft can be completed. .

According to the present embodiment described above, the following effects can be obtained in addition to the effects of the second embodiment. That is, the three-dimensional cam lobes 342 to 348 in which the shaft 314 is fitted and the reference plates 383 to 390 are driven by the swing mechanisms 424 to 430 to support the reference plate support arm 37.
Opening 5-382 separates. Due to this separation, the heat from the reference plates 383 to 390 is not received, and the air flows around the three-dimensional cam lobes 342 to 348 and rapidly flows to the three-dimensional cam lobes 342 to 348.
The 348 is cooled so that a tightly integrated three-dimensional camshaft 450 can be quickly manufactured.

Further, the temperature maintaining circuit 44 is also used in the positioning step.
0 sets the shrink-fit temperature to 3D cam lobes 342-348
3D cam lobe 342-
Since the temperature control of the three-dimensional cam lobes 348 becomes easy and the cooling speed of the three-dimensional cam lobes 342 to 348 does not need to be considered in the positioning step as in the conventional case, as described above, all the three-dimensional cam lobes can be formed in one fitting step. 342 to 348 can be shrink-fitted to the shaft 314 under the same fitting conditions. Therefore, work efficiency is increased, and it is possible to greatly contribute to a reduction in manufacturing cost of the three-dimensional camshaft.

Further, when a plurality of three-dimensional cam lobes 342 to 348 are shrink-fitted to the shaft 314 at a time as described above, all the three-dimensional cam lobes 342 to 348 are controlled by the temperature maintaining circuit 440 regardless of the positioning order and the positioning positions of the three-dimensional cam lobes 342 to 348. Since the temperatures of the three-dimensional cam lobes 342 to 348 can be maintained at the same shrink fitting temperature, the following effects occur. That is, the shaft 314 is heated by receiving heat from the three-dimensional cam lobes 342 to 348 at the time of fitting.
Under the influence of the same temperature at the fitting positions of 42 to 348, the same thermal expansion is always obtained. Therefore, the upper and lower positions of the reference plates 383 to 390 can be precisely set in consideration of the thermal expansion in advance, and the mounting positions of the three-dimensional cam lobes 342 to 348 in the axial direction despite the fact that they are manufactured by a single insertion. The accuracy will be extremely high.

In addition, a plurality of three-dimensional cam lobes 342-3
48 can be attached to the shaft 314 at the same time, so that the attachment accuracy of the three-dimensional cam lobes 342 to 348 in the rotation direction is also improved.

In particular, in the present embodiment, it is possible to manufacture a three-dimensional camshaft with a high accuracy of the mounting position of the three-dimensional cam lobes 342 to 348 in the axial direction. From this, it is possible to realize high precision especially in the adjustment of the lift amount by adjusting the position of the three-dimensional cam in the axial direction.

[Other Embodiments] In the third embodiment, the movable pins 230a and 232a
The lower end surface 111f of the three-dimensional cam lobe 111 is separated from the mounting surface 220s of the reference plate 220 by the projection of the three-dimensional cam lobe 111, and at the same time, a fitting end signal is output from the numerical control device to the temperature maintenance circuit 220d.
The current to 0a and 220b may be cut off.
By doing so, the cooling of the three-dimensional cam lobe 111 is further promoted.

Similarly, the heating of the heaters 383b to 390b may be stopped at the beginning of the cooling step in the fourth embodiment. By doing so, the three-dimensional cam lobe 342
~ 348 cooling is further promoted.

In the above embodiments, a three-dimensional cam lobe is used, but a normal cam lobe whose profile does not change in the axial direction may be used. A cooling function is provided in the temperature adjusting means of the second to fourth embodiments so that when a three-dimensional cam lobe heated to a temperature higher than the shrink fitting temperature is disposed, the temperature is rapidly cooled to the shrink fitting temperature. Is also good.

The function of raising the temperature of the three-dimensional cam lobe from room temperature to the shrink fitting temperature (that is, also performing the temperature adjusting step) is maintained by the temperature adjusting means of the second to fourth embodiments. It may be possible to fulfill both roles. That is, the processing may be performed as in claims 6 and 9.

In each of the above embodiments, the movement and position control of each component are performed by numerical control, but are not limited to numerical control and may be arbitrarily performed. For example, any position control using a limit switch or the like may be used as long as sufficient accuracy is ensured.

In each of the above embodiments, the three-dimensional cam lobe is fixed, and the shaft is moved by numerical control to perform the assembly. This may be changed so that the shaft side is fixed and the three-dimensional cam lobe is moved by a numerical control together with the cam lobe positioning jig and the reference plate. Further, both of them may be changed so as to be moved by numerical control.

In the fourth embodiment, the base 350
It is good also as a structure which stabilizes the temperature of the base 350 by passing cooling water inside. As a result, the three-dimensional cam lobe 34
The mounting accuracy of 2 to 348 can be further improved.

In the above embodiments, various mechanisms / means are controlled by the numerical controller. However, by manually operating the various mechanisms / means, the manufacturing method of each embodiment is executed. You may.

[0165]

According to the first aspect of the present invention, in the heating step, the outer peripheral surface of the cam lobe is heated to a quenching temperature and the inner peripheral surface of the shaft insertion hole of the cam lobe is heated to a squeezing temperature. I do. Since the shrink fitting temperature is lower than the quenching temperature, for example, if the outer peripheral surface is heated to a quenching temperature by a method capable of raising the temperature from the outer peripheral surface of the cam lobe, heat transfer from the outer peripheral surface to the inner peripheral surface Naturally, the temperature of the inner peripheral surface of the shaft fitting hole present inside the cam lobe can be adjusted to the shrink fitting temperature.

In this state, the fitting step is performed, and when the shaft is fitted into the shaft fitting hole heated to the shrink fitting temperature, the shaft absorbs the heat of the cam lobe from the inner peripheral surface side of the shaft fitting hole, and the temperature of the cam lobe is reduced. Decreases rapidly and the temperature of the shaft increases. Thus, the cam lobe and the shaft are shrink-fitted and integrated. Further, the outer peripheral surface of the cam lobe is also rapidly deprived of heat from the shaft insertion hole side by heat conduction, and the temperature rapidly decreases from the quenching temperature. This hardens the outer peripheral surface of the cam lobe.

Since the shrink fitting and the quenching are performed simultaneously by the above-described steps, it is not necessary to quench the outer peripheral surface of the cam lobe in advance. Therefore, there is no problem that tempering occurs during shrink fitting.

Further, since the shrink fitting and the quenching are performed at the same time, there is an additional effect that the number of steps is reduced and the manufacturing efficiency is increased. Furthermore, since it is not necessary to perform heating separately for quenching and shrink fitting, heating is only required once, so that the energy saving effect is high and the heat energy released into the air is small, which is preferable in the global environment.

As set forth in claim 2, when the shrink fitting temperature is a temperature lower than the quenching temperature,
The following effects are obtained. That is, even if the shrink fitting temperature is set to a temperature equal to the quenching temperature, both the hardening of the cam lobe outer circumferential surface and the shrink fitting of the cam lobe inner circumferential surface are possible, but the shrink fitting temperature and the hardening temperature are equal. In this case, the rate of temperature decrease due to the insertion of the shaft at the time of shrink fitting or subsequent cooling becomes slow on the outer peripheral surface side of the cam lobe. For this reason, quenching of the cam lobe outer peripheral surface may become sweet. For this reason, the shrink fitting temperature is preferably lower than the quenching temperature in order to prevent quenching from becoming sweet. Further, even if the shrink fitting temperature is within the temperature range in which shrink fitting is possible, it is better to set the shrink fitting temperature to a range sufficiently lower than the quenching temperature for hardening of the cam lobe outer peripheral surface for the above-described reason. Is preferred for

As described in claim 3, as the heating step, for example, the outer peripheral surface of the cam lobe is heated to the quenching temperature by heating from the outer peripheral surface side of the cam lobe, and the inner peripheral surface of the shaft fitting hole of the cam lobe is heated. When heating to the fitting temperature, the following effects are obtained.

That is, by heating from the outer peripheral surface of the cam lobe, when the outer peripheral surface is heated to the quenching temperature, the inner peripheral surface of the shaft insertion hole can be made lower than the quenching temperature. Since the shrink fitting temperature includes a temperature range lower than the quenching temperature, by adjusting the heating rate of the outer circumferential surface of the cam lobe by heating, the outer circumferential surface of the cam lobe reaches the quenching temperature, The temperature of the inner peripheral surface of the fitting hole can reach the shrink fitting temperature. By heating the outer peripheral surface from the outer peripheral surface at an appropriate heating rate in this manner, the outer peripheral surface of the cam lobe can be easily set to the quenching temperature and the inner peripheral surface of the shaft insertion hole of the cam lobe can be set to the hardening temperature.

As described in claim 4, when the heating from the outer peripheral surface of the cam lobe is realized by, for example, induction heating, the following effects are obtained. For example, if high-frequency heating is performed as one of the induction heating, by adjusting the high-frequency, the heating power, and the heating time, the outer peripheral surface of the cam lobe is set to the quenching temperature,
At the same time, the inner peripheral surface of the shaft fitting hole of the cam lobe can be set to the shrink fitting temperature.

In the camshaft manufacturing method according to the fifth aspect, before the fitting step, the positioning step of positioning the cam lobe whose temperature has been adjusted in the temperature adjusting step while maintaining the shrink fitting temperature by the temperature adjusting means is performed. Be executed. In this positioning step, if the shrink-fitting temperature is not maintained by the temperature adjusting means, that is, if shrink-fitting is performed as in the prior art, in the temperature adjustment step performed immediately before, in the cam lob positioning step, In consideration of cooling, it is necessary to heat to a temperature considerably higher than the shrink fitting temperature. If the temperature is higher than the shrink fitting temperature in this way, tempering occurs and the hardness of the outer peripheral surface of the cam lobe decreases. However, in the present camshaft manufacturing method, since the temperature of the cam lobe can be maintained at the shrink fitting temperature by the temperature adjusting means even in the positioning step, in the temperature adjusting step immediately before the positioning step, heating to almost the shrink fitting temperature is sufficient. Well, no extra heating is required. Therefore, the outer peripheral surface of the cam lobe is not tempered and does not adversely affect quenching.

Further, since the temperature of the cam lobe can be maintained at the shrink-fitting temperature by the temperature adjusting means in the positioning step, the temperature control of the cam lobe is easy, and the cooling speed of the cam lobe in the positioning step is not considered. This eliminates the need for such a step, so that there is a margin in the execution timing of the fitting step, and a secondary effect that yield is improved by stable work is produced. Further, in the temperature adjustment step, a heating furnace or the like for heating the cam lobe can be kept lower than before,
Even taking into account the fact that energy is consumed by the temperature adjusting means, the total energy consumption can be reduced. Therefore, since the energy saving effect is high and the heat energy released into the air is small, it is preferable in the global environment.

In the method for manufacturing a camshaft according to claim 6, the cam lobe is heated to the shrink fitting temperature after the positioning step. Thereafter, the positioned cam lobe is maintained at the shrink fitting temperature. Therefore,
The same operation and effect as described in the fifth aspect are produced.

According to a seventh aspect of the present invention, in the cooling step, a step of separating the cam lobe in which the shaft is fitted into the shaft fitting hole from the temperature adjusting means in the fitting step is performed. , The air flows around the cam lobe, and the cam lobe and the shaft are rapidly cooled, whereby a firmly integrated camshaft can be quickly manufactured.

An eighth aspect of the present invention is different from the fifth, sixth, and seventh aspects in that a plurality of cam lobes are simultaneously fitted into one shaft. Therefore, the following effects are produced in addition to the effects described in the fifth, sixth, and seventh aspects.

That is, in a situation where the temperature adjusting means is not used as in the related art, a plurality of cam lobes are arranged in a line,
When fitting a shaft into the shaft fitting hole,
The cooling state of each cam lobe differs depending on the positioning order and the positioning positions of the cam lobes. For this reason, even if the shafts are simultaneously fitted into all the cam lobes, the temperature condition differs for each cam lobe. That is, since the temperature differs for each cam lobe fitted, the amount of heat received from the cam lobe also varies depending on the position of the shaft. For this reason, the thermal expansion of the shaft may differ depending on the position, and the mounting accuracy of the cam lobe in the axial direction may be reduced. However, since the present camshaft manufacturing method uses the temperature adjusting means, the temperature of the cam lobes is maintained at the same level as the shrink fitting temperature regardless of the positioning order and the positioning positions of the cam lobes when the shaft is fitted. . For this reason, the thermal expansion of the shaft does not differ depending on the position, and the mounting accuracy of the cam lobe in the axial direction does not decrease.

Further, since a plurality of cam lobes can be attached to the shaft at the same time, the productivity can be improved and the cost can be reduced, and the relative position between the cam lobes can be accurately set. The mounting accuracy is also improved.

According to a ninth aspect of the present invention, after the positioning step, all the cam lobes are heated to the shrink fitting temperature. Thereafter, all the cam lobes positioned are maintained at the shrink fitting temperature. Therefore, the same function and effect as described in claim 8 are obtained.

As described in the tenth aspect, if a three-dimensional cam lobe is used as the cam lobe, especially when a plurality of the cam lobes are shrink-fitted at once as in the eighth and ninth aspects, the axial direction of the cam lobe is reduced for the above-described reason. A three-dimensional camshaft with high mounting position accuracy can be manufactured. From this, it is possible to realize high precision especially in the adjustment of the lift amount by adjusting the position of the three-dimensional cam in the axial direction.

The cam lobe positioning jig according to the eleventh aspect is used in the above-described positioning step of the camshaft manufacturing method, so that the cam lobe whose temperature has been adjusted in the temperature adjusting step is shrink-fitted by the temperature adjusting means. Positioning can be performed in the state maintained, and the above-described effects can be produced.

By configuring the camshaft manufacturing apparatus as described in claim 12, it can be used as an apparatus for realizing the camshaft manufacturing method of claim 1. Further, by configuring the camshaft manufacturing apparatus as described in claim 13, it can be used as an apparatus for realizing the camshaft manufacturing method of claim 2. Further, by configuring the camshaft manufacturing apparatus as described in claim 14, it can be used as an apparatus for realizing the camshaft manufacturing method of claim 3. By configuring the camshaft manufacturing apparatus as described in claim 15, the apparatus can be used as an apparatus for realizing the camshaft manufacturing method of claim 4. In addition, by configuring the camshaft manufacturing apparatus as described in claim 16, it can be used as an apparatus for realizing the camshaft manufacturing method according to claims 5 and 6. In addition, by configuring the camshaft manufacturing apparatus as described in claim 17,
The camshaft manufacturing method according to claim 7 can be used as an apparatus for realizing the method. In addition, by configuring the camshaft manufacturing apparatus as described in claim 18, it can be used as an apparatus for realizing the camshaft manufacturing method according to claims 8 and 9. In addition, by configuring the camshaft manufacturing apparatus as described in claim 19, claim 10 is provided.
Can be used as an apparatus for realizing the camshaft manufacturing method.

[Brief description of the drawings]

FIG. 1 is a plan view of a three-dimensional cam lobe used for manufacturing a three-dimensional camshaft according to a first embodiment.

FIG. 2 is a bottom view of the three-dimensional cam lobe.

FIG. 3 is a longitudinal sectional view of the three-dimensional cam lobe.

FIG. 4 is a partial perspective view of the three-dimensional camshaft according to the first embodiment.

5 is a partial perspective view of the three-dimensional camshaft in which the three-dimensional camshaft of FIG. 4 is turned upside down.

FIG. 6 is a longitudinal sectional view showing the three-dimensional camshaft manufacturing apparatus according to the first embodiment.

FIG. 7 is an explanatory diagram of a temperature distribution of a three-dimensional cam lobe performed in a heating step according to the first embodiment.

FIG. 8 is an explanatory diagram illustrating a manufacturing procedure of the three-dimensional camshaft according to the first embodiment.

FIG. 9 is an explanatory diagram illustrating a manufacturing procedure of the three-dimensional camshaft according to the first embodiment.

FIG. 10 is an explanatory diagram illustrating a manufacturing procedure of the three-dimensional camshaft according to the first embodiment.

FIG. 11 is an explanatory diagram illustrating a manufacturing procedure of the three-dimensional camshaft according to the first embodiment.

FIG. 12 is an explanatory diagram of a three-dimensional cam lobe structure used for manufacturing a three-dimensional cam shaft according to the second embodiment.

FIG. 13 is a partial perspective view of a three-dimensional camshaft according to the second embodiment.

FIG. 14 is an explanatory diagram showing a structure of a cam lobe positioning jig according to the second embodiment.

FIG. 15 is a longitudinal sectional view showing a three-dimensional camshaft manufacturing apparatus according to a second embodiment.

FIG. 16 is an explanatory diagram illustrating a manufacturing procedure of the three-dimensional camshaft according to the second embodiment.

FIG. 17 is an explanatory diagram illustrating a procedure for manufacturing a three-dimensional camshaft according to the second embodiment.

FIG. 18 is an explanatory diagram illustrating a procedure for manufacturing the three-dimensional camshaft according to the second embodiment.

FIG. 19 is an explanatory diagram illustrating a procedure for manufacturing a three-dimensional camshaft according to the second embodiment.

FIG. 20 is a longitudinal sectional view of a reference plate according to the third embodiment.

FIG. 21 is a longitudinal sectional view of a reference plate according to the third embodiment.

FIG. 22 is a longitudinal sectional view showing a three-dimensional camshaft manufacturing apparatus according to a third embodiment.

FIG. 23 is an explanatory diagram illustrating a procedure for manufacturing a three-dimensional camshaft according to the third embodiment.

FIG. 24 is an explanatory diagram illustrating a procedure for manufacturing a three-dimensional camshaft according to the third embodiment.

FIG. 25 is an explanatory diagram illustrating a manufacturing procedure of the three-dimensional camshaft according to the third embodiment.

FIG. 26 is an explanatory diagram illustrating a procedure for manufacturing a three-dimensional camshaft according to the third embodiment.

FIG. 27 is a configuration explanatory view of a three-dimensional camshaft manufacturing apparatus according to a fourth embodiment.

FIG. 28 is a partial perspective view showing a configuration of a cam lobe positioning jig and a reference plate according to a fourth embodiment.

FIG. 29 is a partial perspective view showing a configuration of a cam lobe positioning jig and a reference plate according to the fourth embodiment.

FIG. 30 is an explanatory diagram showing a procedure for manufacturing a three-dimensional camshaft according to the fourth embodiment.

FIG. 31 is an explanatory diagram showing a procedure for manufacturing a three-dimensional camshaft according to the fourth embodiment.

FIG. 32 is an explanatory diagram illustrating a procedure for manufacturing the three-dimensional camshaft according to the fourth embodiment.

FIG. 33 is an explanatory view showing a procedure for manufacturing a three-dimensional camshaft according to the fourth embodiment.

[Explanation of symbols]

10 ... three-dimensional camshaft manufacturing device, 11, 11 '... 3
Dimensional cam lobe, 11a ... cam nose, 11b, 11b '
... outer peripheral surface, 11c ... inner peripheral surface, 12, 12 '... shaft insertion hole, 13, 13' ... insertion hole, 14, 15 ... projection 14,
15, 14 ... projection, 16 ... shaft, 17 ... fitting hole, 1
8 Pin, 19 Chuck, 20 Jig base 20, 20
a: Reference plate, 21: Through hole, 22: Center pin, 23:
Spring, 24 ... Phase setting pin, 25 ... Clamper, 2
6 high frequency coil, 27 temperature sensor, 28 temperature control device, 29 high frequency power supply, 109 three-dimensional camshaft manufacturing device, 110 three-dimensional camshaft, 111, 11
1 ': three-dimensional cam lobe, 111a: upper end face, 111b ...
Intermediate position, 111c: lower end face, 111d: nose, 11
1e: outer peripheral surface, 111f: lower end surface, 112: parallel portion, 1
13: shaft insertion hole, 114: shaft, 115, 1
16 ... jig, 117, 118 ... V-shaped groove, 119 ... base,
120: Reference plate, 120a, 120b: Heater, 120
c: temperature sensor, 120d: temperature maintaining circuit, 121:
Holes: 122, clamper, 123: chuck, 124: pin, 126: insertion hole, 202: three-dimensional camshaft manufacturing device, 220: reference plate, 220a, 220b: heater,
220c: temperature sensor, 220d: temperature maintaining circuit, 22
0s: mounting surface, 220t, 220u: pin receiving hole, 23
0,232 ... Cam lobe lifting mechanism, 230a, 232
a: movable pin, 230b, 232b: first hydraulic chamber, 23
0c, 232c: second hydraulic chamber, 230d, 232d: sliding end, 234: hydraulic source, 236: hydraulic circuit, 310:
Three-dimensional camshaft manufacturing device, 314 ... shaft, 34
2,344,346,348 ... Cam lob, 342a, 3
44a, 346a, 348a ... bottom surface, 342b, 344
b, 346b, 348b: shaft insertion hole, 350: base, 352, 353, 354, 355, 356, 35
7,358,359 ... Jig support arm, 360,36
1,362,363,364,365,366,367
... Cam lobe positioning jig, 360a, 361a, 362
a, 363a, 364a, 365a, 366a, 367
a ... groove, 368, 370, 372, 374 ... cam lobe arrangement hole, 375, 376, 377, 378, 379, 38
0, 381, 382: Support arm for reference plate, 383, 3
84, 385, 386, 387, 388, 389, 39
0: Reference plate, 383a, 384a, 385a, 386
a, 387a, 388a, 389a, 390a ... groove, 3
83b, 384b, 385b, 386b, 387b, 3
88b, 389b, 390b ... heater, 383c, 38
4c, 385c, 386c, 387c, 388c, 38
9c, 390c: temperature sensor, 383s, 384s, 3
85s, 386s, 387s, 388s, 389s, 3
90s: mounting surface, 384b, 386b, 388b, 39
0b: heater, 392, 394, 396, 398: shaft through hole, 400, 402, 404, 406, 40
8, 410, 412, 414 heat insulator, 416, 41
8,420,422,424,426,428,430
… Swing mechanism, 440 temperature maintaining circuit, 450 three-dimensional camshaft.

Claims (19)

[Claims] 1. A method of manufacturing a camshaft by assembling a shaft into a shaft fitting hole of a cam lobe by shrink fitting, wherein an outer peripheral surface of the cam lobe is heated to a quenching temperature and an inner periphery of the shaft fitting hole of the cam lobe. A method of manufacturing a camshaft, comprising: performing a heating step of heating a surface to a shrink fitting temperature; and a fitting step of fitting a shaft into a shaft fitting hole of the cam lobe heated in the heating step. 2. The method according to claim 1, wherein the shrink fitting temperature is lower than the quenching temperature. 3. The camshaft manufacturing method according to claim 1, wherein the heating step is performed by heating from an outer peripheral surface side of the cam lobe. 4. The method according to claim 3, wherein the heating is performed by induction heating. 5. A method for manufacturing a camshaft by assembling a shaft into a shaft fitting hole of a cam lobe whose outer peripheral surface is quenched by a shrink fitting method, comprising: a temperature adjusting step of adjusting the temperature of the cam lobe to substantially a shrink fitting temperature; The cam lobe whose temperature has been adjusted in the temperature adjustment step,
A positioning step of positioning the shrink-fitting temperature while maintaining the shrink-fitting temperature by the temperature adjusting means; a fitting step of fitting a shaft into the shaft fitting hole of the cam lobe positioned in the positioning step; A cooling step of cooling the cam lobe and the shaft obtained. 6. A method of manufacturing a camshaft by assembling a shaft into a shaft fitting hole of a cam lobe whose outer peripheral surface is quenched by hardening, wherein a positioning step of positioning the cam lobe; A temperature adjusting step of adjusting the temperature of the cam lobe to a shrink-fitting temperature by temperature adjusting means; and fitting the shaft into a shaft fitting hole of the cam lobe whose temperature has been adjusted to the shrink-fitting temperature in the temperature adjusting step. And a cooling step of cooling the cam lobe and the shaft integrated in the fitting step. 7. The cooling step is performed by separating the temperature adjusting means from the cam lobe in which a shaft is fitted in a shaft fitting hole in the fitting step. Of manufacturing camshafts. 8. A method of manufacturing a camshaft by assembling one shaft into each shaft fitting hole of a plurality of cam lobes whose outer peripheral surfaces are quenched by hardening, wherein each cam lobe is substantially heated to a shrink fitting temperature. A temperature adjustment step of adjusting; a positioning step of positioning all of the cam lobes whose temperatures have been adjusted in the temperature adjustment step in a row while maintaining a shrink fitting temperature by a temperature adjustment means; and a positioning step of positioning in the positioning step. A fitting step of simultaneously fitting one shaft into the shaft fitting holes of all the cam lobes, and all the cam lobes whose shafts are fitted into the shaft fitting holes in the fitting step and the temperature adjusting means. A method of manufacturing a camshaft, comprising: performing a cooling step of simultaneously separating; 9. A method of manufacturing a camshaft by assembling one shaft into each shaft fitting hole of a plurality of cam lobes whose outer peripheral surfaces are quenched by hardening, wherein all cam lobes are aligned in a line. A temperature adjusting step of adjusting the temperature of all of the cam lobes positioned in the positioning step to a shrink-fitting temperature by a temperature adjusting means; and adjusting the temperature to the shrink-fitting temperature in the temperature adjusting step. At the same time, all cam lobe shaft insertion holes
A fitting step of fitting one shaft; and a cooling step of simultaneously separating all the cam lobes having the shaft fitted into the shaft fitting holes in the fitting step and the temperature adjusting means. Camshaft manufacturing method. 10. The method according to claim 1, wherein the cam lobe is a three-dimensional cam lobe. 11. A positioning device for positioning a cam lobe at a shaft insertion position when a camshaft is manufactured by shrink-fitting a shaft into a shaft insertion hole of the cam lobe, wherein the cam lobe is positioned at the shaft insertion position. And a temperature adjusting means for maintaining the temperature at the shrink fitting temperature. 12. An apparatus for manufacturing a camshaft by assembling a shaft into a shaft insertion hole of a cam lobe by shrink fitting, comprising: positioning means for positioning the cam lobe at a shaft insertion position; and said positioning means being positioned by the positioning means. Heating means for heating the cam lobe; heating control means for controlling the heat treatment by the heating means so that the outer peripheral surface of the cam lobe is at a quenching temperature and the inner peripheral surface of the shaft fitting hole of the cam lobe is at a squeezing temperature. And a shaft fitting means for fitting a shaft into a shaft fitting hole of the cam lobe which is positioned by the positioning means and heated by the heating means controlled by the heating control means. Camshaft manufacturing equipment. 13. The camshaft manufacturing apparatus according to claim 12, wherein the shrink fitting temperature is lower than the hardening temperature. 14. The heating device according to claim 12, wherein the heating means heats the outer periphery of the cam lobe.
3. The camshaft manufacturing apparatus according to 3. 15. The apparatus according to claim 14, wherein the heating unit is an induction heating device. 16. An apparatus for manufacturing a camshaft by assembling a shaft into a shaft insertion hole of a cam lobe whose outer peripheral surface is quenched by hardening, comprising: positioning means for positioning the cam lobe at a shaft insertion position; and said positioning means. A temperature adjusting means for maintaining the temperature of the cam lobe positioned at the shaft fitting position at the shrink fitting temperature, and a shaft of the cam lob positioned at the positioning step and maintained at the shrink fitting temperature by the temperature adjusting means. A camshaft manufacturing apparatus, comprising: a shaft fitting means for fitting a shaft into a fitting hole. 17. The configuration of the camshaft manufacturing apparatus according to claim 16, further comprising a cooling unit for separating the temperature adjusting unit from the cam lobe in which the shaft is inserted into the shaft insertion hole by the shaft insertion unit. A camshaft manufacturing apparatus characterized in that: 18. An apparatus for manufacturing a camshaft by assembling one shaft into each shaft insertion hole of a plurality of cam lobes whose outer peripheral surfaces are quenched by hardening, wherein all the cam lobes are aligned in a shaft insertion position. Positioning means for positioning the cam lobes positioned at the shaft fitting positions by the positioning means at a shrink-fitting temperature; and Shaft fitting means for fitting one shaft simultaneously into the shaft fitting holes of all the cam lobes maintained at the shrink fitting temperature; and all the shafts fitted into the shaft fitting holes by the shaft fitting means. A cooling unit for simultaneously separating the cam lobe and the temperature adjusting unit from each other. Yafuto manufacturing equipment. 19. The camshaft manufacturing apparatus according to claim 12, wherein said cam lobe is a three-dimensional cam lobe.