JPH0625615Y2 - Bearing device for camshaft in internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a cam shaft for an intake valve and / or an exhaust valve in an internal combustion engine, a thrust receiving disk for the cam shaft, a fuel pump, and / or a distributor. The present invention relates to a bearing device for the cam shaft, which is provided with a drive unit for an auxiliary machine.

[Conventional technology]

In a bearing device for a camshaft described in Japanese Utility Model Laid-Open No. 59-67509, which is a prior art, a bearing seat is integrally provided on a cylinder head, and a semicircular bearing hole formed in this bearing seat and the bearing seat are formed. A journal portion of the cam shaft is rotatably supported by a semicircular bearing hole formed in a bearing cap body for fastening, and the cam shaft has a thrust receiving disk and a fuel pump or the like at a position at an outer end portion of the journal portion. A lower housing is provided on the outer side of the bearing seat of the cylinder head, and an upper housing that is joined to the lower housing is integrally provided on the outer side of the bearing cap body while integrally providing a drive section for the auxiliary machine. In the lower housing and the upper housing, a housing chamber for the thrust receiving disk of the cam shaft and the auxiliary drive unit is formed, and further, in the upper housing of the housing chambers. Only the upper half of the thrust bearing disc in the cam shaft had to be provided with a full thrust receiving groove fitting.

As in this prior art, a structure is provided in which a thrust receiving groove into which only the upper half of the thrust receiving disk of the cam shaft is fitted is provided in the upper housing integrated with the bearing cap body that is fastened to the bearing seat in the cylinder head. In this case, the semicircular bearing hole in the bearing seat of the cylinder head is in communication with the accommodating chamber, and the lubricating oil supplied to the journal smoothly moves toward the back surface of the thrust receiving disk and the accommodating chamber. By flowing out, it can be stored in the accommodating chamber, so that there is an advantage that the thrust receiving disk and the accessory drive unit can be reliably lubricated.

[Problems to be solved by the invention]

However, on the other hand, the lubrication device of the prior art has a problem in that it is difficult to fully automate the assembly of the cam shaft with respect to the cylinder head by the robot device, as described below.

That is, the cam shaft is assembled to the cylinder head by first mounting the cam shaft on the upper surface of the cylinder head such that the lower half of the journal portion of the cam shaft fits into the semicircular bearing hole in the bearing seat of the cylinder head. Then, the bearing cap body with the upper housing is fitted to the cam shaft, and the bearing cap body is fastened to the bearing seat. It is determined by fitting the thrust receiving disk provided on the cam shaft into the thrust receiving groove provided on the upper housing that is integral with the bearing cap body.

On the other hand, when the bearing cap body with the upper housing is fastened to the bearing seat on the cylinder head side, the fastening bolts should be fitted with knock pins that closely fit both the bearing cap body and the bearing seat. Therefore, in the case where the upper housing integrated with the bearing cap body is provided with the thrust receiving groove into which only the upper half of the thrust receiving disk of the cam shaft is fitted as in the prior art, When fitting the bearing cap body to the cam shaft, the thrust bearing disc of the bearing cap body is fitted with the thrust bearing disk of the cam shaft, and the knock pin hole of the bearing cap body is fitted with the knock pin of the cylinder head side. They must fit together at the same time.

However, when the thrust receiving groove of the camshaft is provided with the thrust receiving groove into which only the upper half of the disk is fitted, as in the prior art, the upper housing integrated with the bearing cap body has the upper surface of the cylinder head. When the cam shaft is mounted so that the lower half of the journal portion of the cam shaft fits into the semicircular bearing hole in the bearing seat of the cylinder head, the axial mounting position of the cam shaft becomes undecided. In other words, in the state where the journal portion of the cam shaft is fitted in the bearing seat of the cylinder head, the cam shaft shifts in the axial direction of the bearing seat. The thrust receiving disk of the camshaft is in the groove,
This makes it extremely difficult to fit the knock pins on the cylinder head side into the knock pin holes in the bearing cap body at the same time so that the knock pins are fitted on the cam shaft.

An object of the present invention is to solve the above-mentioned problems of the prior art while maintaining the lubricity of the thrust receiving disk and the drive of the auxiliary machine.

[Means for solving problems]

To achieve this object, the present invention provides a cylinder head integrally with a bearing seat, and a semicircular bearing hole formed in the bearing seat and a semicircular bearing hole formed in a bearing cap body fastened to the bearing seat. The journal part of the cam shaft is supported by the cam shaft, and the cam shaft is provided with a thrust receiving disk and a drive part for auxiliary machinery such as a fuel pump at a position on the outer end side of the journal part. A lower housing is integrally provided on the outer side of the bearing seat, and an upper housing that is joined to the lower housing is integrally provided on the outer side of the bearing cap body, and the thrust of the cam shaft is provided in the lower housing and the upper housing. In a bearing device for a cam shaft, which forms a housing chamber for a receiving disk and an auxiliary machine drive unit, a thrust in the cam shaft is provided in a lower housing of the housing chamber. A thrust receiving groove into which only the substantially lower half of the circular plate is fitted is provided, and an oil groove that connects the bottom surface of the semicircular bearing hole of the bearing seat and the storage chamber is provided so as to cross the thrust receiving groove. I made it up.

[Function and effect of device]

Thus, by providing the thrust receiving groove in which only the lower half of the thrust receiving disk of the cam shaft fits in the lower housing shaped on the cylinder head side, the cam shaft is Simply mount the journal so that the thrust receiving disk fits in the semicircular bearing hole of the bearing seat and the thrust receiving groove, respectively.
The cam shaft can be positioned with respect to the cylinder head so that the cam shaft does not move in the axial direction. In other words, the mounting position of the cam shaft in the axial direction with respect to the cylinder head is integrated with the cylinder head. By fitting the thrust receiving disc into the thrust receiving groove provided in the lower housing, the bearing will be automatically positioned at the proper position. Then, the bearing cap with the upper housing is fitted on the journal portion of the camshaft. The bearing cap body can be easily assembled to the cylinder head incomparably compared with the prior art.

However, when the thrust receiving groove is provided in the lower housing integrated with the cylinder head and the thrust receiving disk of the cam shaft is fitted in the thrust receiving groove in this manner, the lubricating oil for the journal portion of the cam shaft is prevented. ,
It becomes difficult for the back surface of the thrust receiving disk and the storage chamber to flow, and there is a shortage of lubricating oil for the back surface of the thrust receiving disk and the drive unit for the auxiliary machine.

Therefore, in order to solve this problem, the present invention provides an oil groove for communicating the bottom surface of the semicircular bearing hole of the bearing seat with the storage chamber.
The thrust receiving groove is provided so as to cross the thrust receiving groove. With this structure, the lubricating oil supplied to the journal portion of the cam shaft passes through the oil groove that crosses the thrust groove, and then the thrust receiving disc. Since it smoothly flows out to the back surface and the storage chamber side and accumulates in the storage chamber, it is possible to reliably lubricate the back surface of the thrust receiving disk and the auxiliary drive unit.

Therefore, according to the present invention, it is extremely easy to fully automate the assembly of the cam shaft with respect to the cylinder head by the robot device without impairing the lubricity of the thrust bearing portion and the accessory drive portion of the cam shaft. Have.

〔Example〕

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A bearing seat 4 having a semicircular bearing hole 5 into which a lower half of the bearing 3 is fitted is integrally provided, and a lower housing 6 is integrally provided at an outer end portion of the bearing seat 4.

On the other hand, the cam shaft 2 is integrally provided with a thrust receiving disk 8 at an outer end portion of the journal portion 3 and an eccentric cam 9 for driving a fuel pump (not shown). .

Reference numeral 10 indicates a bearing cap body provided with a semicircular bearing hole 11 fitted in the upper half of the journal portion 3 of the cam shaft 2, and the bearing cap body 10 has bolt holes 12 formed on both left and right sides thereof. It is fastened to the bearing seat 4 of the cylinder head 1 by a pair of left and right bolts 13 inserted in the.

Further, an upper housing 10a joined to the lower housing 6 is integrally formed on the outer surface of the bearing cap body 10 when the bearing cap body 10 is fastened to the bearing seat 4 of the cylinder head 1. The upper housing 10a and the lower housing 6 are provided.
And the thrust receiving disk 8 in the cam shaft 2 inside
And the storage chamber 7 for the eccentric cam 9 is formed.

A thrust receiving groove 14 into which the lower half of the thrust receiving disk 8 of the cam shaft 2 is fitted is formed in the lower housing 6 of the accommodation chamber 7, and the semicircular bearing of the bearing seat 4 is formed. An oil groove 15 that connects the bottom surface of the hole 5 and the inside of the accommodation chamber 7 is provided so as to cross the thrust receiving groove 14.

It should be noted that at least one of the bolts 13 for fastening the bearing cap body 10 to the bearing seat 4 is closely fitted to both the bearing seat 4 and the bearing cap body 10. The knock pin 16 thus formed is fitted. Further, in the figure, reference numeral 17 indicates a cylinder head cover, reference numerals 18 and 19 indicate swing arm shafts, and both swing arm shafts 18 and 19 indicate the bearing cap body 10.
Are simultaneously fastened to the upper surface of the fastening shaft 13 by both fastening bolts 13. Lubricating oil for the shaft portion 3 of the cam shaft 2 is supplied to the bolt holes 12 of the fastening bolts 13 from both swing arm shafts 18 and 19. It is configured to be supplied via. Furthermore, the housing 6 is provided with a distributor 20 detachably connected to the cam shaft 2 at one end through a joint (not shown).

As described above, by providing the thrust receiving groove 14 into which only the lower half of the thrust receiving disk 8 of the cam shaft 2 is fitted in the lower housing 6 formed on the cylinder head 1 side, the cam shaft 2 is moved to the cylinder head. 1, the journal portion 3 has a semicircular bearing hole 5 in the bearing seat 4 with respect to the upper surface.
In addition, the thrust receiving disk 8 has the thrust receiving groove 14
When the cam shaft 2 is mounted on the cam shaft 2, the axial mounting position of the cam shaft 2 is automatically determined to be a proper position. When fitting, the cylinder head 1 is inserted into the knock pin hole of the bearing cap body 10.
It suffices that the knock pin 16 previously planted on the side be fitted.

Further, a part of the lubricating oil supplied to the journal portion 3 from both the swing arm shafts 18 and 19 through the bolt holes 12 of the fastening bolts 13 flows into the housing chamber 7 through the oil groove 15. Then, by accumulating in the accommodation chamber 7, the back surface of the thrust receiving disk 8 and the eccentric cam 9 for driving the fuel pump, and the coupling joint portion between the cam shaft 2 and the distributor 20 are lubricated. It is.

The lubricating oil that has flowed into the accommodation chamber 7 is guided to the upper chamber 2a of the cylinder head 2 through the groove 21 and then through the oil drop hole 22 provided in the cylinder head 2 to the crankcase (see FIG. Return to (not shown).

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a vertical front view, Fig. 2 is a plan view of a cylinder head, and Fig. 3 is III of Fig. 1.
-III enlarged cross-sectional view, FIG. 4 is an IV-IV enlarged cross-sectional view of FIG. 1 ... Cylinder head, 2 ... Cam shaft, 3 ... Journal section, 4 ... Bearing seat, 5 ... Semi-circular bearing hole, 6 ... Lower housing, 7 ... Storage chamber, 8 ... Thrust receiving circle Board,
9 ... Eccentric cam for driving fuel pump, 10 ... Bearing cap body, 10a ... Upper housing, 11 ... Semi-circular bearing hole, 14 ... Thrust receiving groove, 15 ... Oil groove.

Claims (1)

[Scope of utility model registration request] 1. A bearing seat is integrally provided on a cylinder head,
The semicircular bearing hole formed in the bearing seat and the semicircular bearing hole formed in the bearing cap body fastened to the bearing seat rotatably support the journal portion of the camshaft, and the camshaft has a journal portion more than the journal portion. A thrust receiving disk and a drive unit for an auxiliary machine such as a fuel pump are provided at the outer end portion, while a lower housing is provided outside the bearing seat in the cylinder head, and the lower housing is provided outside the bearing cap body. An upper housing that is to be joined to each other is integrally provided, and a housing chamber for the thrust receiving disk of the cam shaft and a drive unit for an auxiliary machine is formed in the lower housing and the upper housing. In the bearing device, a thrust receiving groove into which only a substantially lower half of a thrust receiving disk of the cam shaft is fitted is provided in the lower housing of the accommodation chamber, and the bearing seat is provided. An oil groove communicating with the bottom surface of the semi-circular bearing hole and the accommodating chamber, the bearing device of the camshaft in an internal combustion engine, characterized in that provided so as to cross the thrust receiving groove.