JPH0710001Y2 - Bearing device for camshaft in internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention comprises a cam shaft for opening and closing an intake valve and a cam shaft for opening and closing an exhaust valve provided in parallel to the upper surface of a cylinder head. The present invention relates to a bearing device for axially supporting each of the cam shafts with respect to a cylinder head in a so-called DOHC type internal combustion engine.

[Conventional technology]

Generally, a camshaft bearing device in a DOHC type internal combustion engine, as described in JP-A-57-52610,
A bearing portion for the cam shaft for opening and closing the intake valve is integrally provided on the upper surface of one side of the cylinder head, and a bearing portion for the cam shaft for opening and closing the exhaust valve is integrally provided on the upper surface of the other side of the cylinder head. A bearing cap body having a bearing hole into which the lower half of each cam shaft is fitted is formed on the bearing portion, and a bearing cap body having a bearing hole into which the upper half of each cam shaft is fitted is placed on the upper surface of each bearing portion. Then, one side of each of the bearing cap bodies sandwiching the cam shaft is fastened to the bearing portion with a bearing bolt, while the other side of each bearing cap body sandwiching the cam shaft is fastened to the cylinder block to the cylinder block. The head bolt is used to fasten the bearing portion.

[Problems to be solved by the device]

By the way, the finish machining of the bearing hole of each bearing portion and the bearing hole of each bearing cap body in the cylinder head is performed with each bearing cap body attached to each bearing portion in order to improve the machining accuracy. Is.

However, as in the prior art, in the configuration in which the other side of each bearing cap body is simply fastened to each bearing portion in the cylinder head by the head bolt, the bearing hole of each bearing portion and the bearing hole of each bearing cap body are When finishing, the cylinder head must be attached to the cylinder block one by one, so it is extremely difficult to finish the bearing hole of each bearing part and the bearing hole of each bearing cap body. There was a problem that the cost required would increase significantly.

An object of the present invention is to provide a bearing device for a camshaft that solves this problem.

[Means for Solving the Problems]

In order to achieve this object, the present invention rotatably supports a cam shaft arranged on the upper surface of a cylinder head with a bearing portion integrally provided on the cylinder head and a bearing cap body attached to the bearing portion. One side of the bearing cap body sandwiching the cam shaft is fastened to the bearing portion with a bearing bolt, while the other side of the bearing cap body sandwiching the cam shaft is connected to the cylinder head. In a bearing device which is fastened to the bearing portion with a head bolt for fastening to a cylinder block, a bolt insertion hole into which an auxiliary fastening bolt for the other side is fitted is formed on the other side of the bearing cap body. On the other hand, a female screw hole for the auxiliary fastening bolt is formed in the bearing portion of the cylinder head.

[Function and effect of device]

According to this structure, when finishing the bearing hole of the bearing portion of the cylinder head and the bearing of the bearing cap body, one side of the bearing cap body is fastened to the bearing portion with the bearing bolt, while the bearing cap body is fastened. Since the bearing cap body can be attached to the cylinder head by fastening the other side of the bearing to the bearing portion with the auxiliary fastening bolt, the bearing cap body can be attached to the bearing hole of the bearing portion in the cylinder head without attaching the cylinder head to the cylinder block. Therefore, it is possible to finish the bearing hole of the bearing cap body.

Therefore, according to the present invention, the finishing work of the bearing hole of the bearing portion of the cylinder head and the bearing hole of the bearing cap body can be performed with the cylinder head removed from the cylinder block. The effect of significantly reducing the time and effort required for finishing the bearing hole of the bearing part and the bearing hole of the cap body, and significantly reducing the machining cost of the bearing hole of the bearing part and the bearing hole of the bearing cap body of these cylinder heads. Have.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In the drawings, reference numeral 1 indicates a cylinder block having a cylinder bore 2, and reference numeral 3 indicates a cylinder head on an upper surface of the cylinder block 1, respectively. 3, an intake port 5 with an intake valve 4 opened on one side thereof
And the exhaust port 7 with the exhaust valve 6 opened on the other side,
The cylinder bores 2 are symmetrically provided with the axis of the cylinder bore 2 interposed therebetween.

Upper surface chambers 8 are integrally provided at one side portion and the other side portion of the upper surface of the cylinder head 3, and a cam shaft 9 for the intake valve 4 is provided in the upper surface chamber 8 at the one side portion. , Cam shafts 10 for the exhaust valve 6 are arranged in parallel with each other in the upper surface chamber 8 near the other side.
The lower half of 10 is rotatably fitted in a bearing hole 12 of a bearing portion 11 provided integrally in each of the upper chambers 8, while each of the bearing portions 11 has each of the cam shafts 9, 10 therein. A bearing cap body (14) having a bearing hole (13) into which the upper half of which is fitted is placed.

Then, the cam shafts 9 and 10 in the bearing cap bodies 14 are
One of the two sides of the bearing head 11 that is located closer to the outside of the cylinder head 3 is attached to the bearing bolts 15 with respect to the bearing portions 11.
On the other hand, the head bolts 16 for fastening the cylinder head 3 to the cylinder block 1 are inserted on the other side of the bearing cap bodies 14 with the cam shafts 9 and 10 interposed therebetween. The other side of the bearing cap body 14 is fastened to the bearing portion 11 with the head bolt 16.

Further, on the other side of each bearing cap body 14, a bolt insertion hole 18 into which an auxiliary fastening bolt 17 having a smaller diameter than the bearing bolt 15 and the head bolt 6 is fitted is formed,
A female screw hole 19 into which the auxiliary fastening bolt 17 is screwed is formed in each bearing 11.

In this structure, the bearing cap body 14 has the bearing bolt 15 on one side and the head bolt 16 on the other side (or the head bolt 16 and the auxiliary fastening bolt 17).
Since they are fastened to each bearing 11, each camshaft
9,10 can be pivoted.

When finishing the bearing hole 12 in each bearing portion 11 and the bearing hole 13 in each bearing cap body 14, one side of each bearing cap body 14 is attached to the bearing bolt 15 as shown in FIG. While each of the bearing caps 14 is fastened to each bearing portion 11 and the other side of each bearing cap body 14 is fastened to the bearing portion 11 by the auxiliary fastening bolts 17, each bearing cap is not attached to the cylinder block 1. Since the body 14 can be attached to the bearing 11,
The labor required for finishing the bearing holes 12 and 13 in the bearing cap body 14 and the bearing cap body 14 is significantly reduced compared to the conventional case, and the cost required for the finishing can be significantly reduced.

It should be noted that the auxiliary fastening bolt 17 is strong enough to fasten the other side of the bearing cap body 14 to the bearing portion 11 when finishing the bearing holes 12 and 13 of the bearing portion 11 and the bearing cap body 14. Suffice, its diameter to bearing bolt
Since the diameter can be made smaller than 15, the bearing cap body 14 does not become excessively large due to the provision of the auxiliary fastening bolts 17.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a vertical sectional front view showing the main part of an internal combustion engine, Fig. 2 is an exploded view, and Fig. 3 is a state in which bearing holes are finished. FIG. 1 ... Cylinder block, 3 ... Cylinder head, 4 ...
... intake valve, 5 ... intake port, 6 ... exhaust valve, 7 ... exhaust port, 8 ... top chamber, 9,10 ... cam shaft, 11 ... bearing part, 12,13 ... bearing hole, 14 …… Bearing cap body, 17 ……
Auxiliary fastening bolt, 18 ...... bolt insertion hole, 19 ... female screw hole.

Claims (1)

[Scope of utility model registration request] 1. A camshaft disposed on the upper surface of a cylinder head is axially supported by a bearing portion integrally provided on the cylinder head and a bearing cap body attached to the bearing portion. One side of the cam shaft sandwiching the cam shaft is fastened to the bearing portion with a bearing bolt, while the other side of the bearing cap body sandwiching the cam shaft is fastened to the cylinder block. In the bearing device configured to be fastened to the bearing portion with a head bolt for, a bolt insertion hole into which an auxiliary fastening bolt for the other side is fitted is formed on the other side of the bearing cap body, and A bearing device for a camshaft in an internal combustion engine, wherein a female screw hole for the auxiliary fastening bolt is bored in a bearing portion of the cylinder head.