JP2000080906A - Spindle device for rocker arm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote the compactification of a cylinder head and a head cover by enhancing the ease of assembly and maintenance even as pivoting each rocker arm with each individual rocker shaft, and reducing a space between two rocker shafts. SOLUTION: Two rocker shafts 38 and 38 are installed side by side in a rocker arm chamber 20a of a tilting type overhead valve engine with a pent roof type combustion chamber 17 and thereby two pivoting parts 13a and 13a of respective rocker arms 13 and 13 are pivoted. Two spindle receiving seats 37a and 37b are installed crosswise in the rocker arm chamber 20a, and two seating parts 38a and 38b formed at both ends of each rocker shaft 38 are locked to these spindle receiving seats 37a and 37b. Then, both the symmetrically paired spindle receiving seats 37a and 37a at the inclined upper side are set up on the inside of each of valve spring bearing seats 33 and 33, thereby making up them into an almost V-form in a state of going along respective suction and exhaust valve shafts 15 and 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft device for a rocker arm applied to an inclined overhead valve engine having a pent roof type combustion chamber.

[0002]

2. Description of the Related Art Conventionally, as a valve train of an inclined overhead valve engine, for example, a valve train shown in FIG.
5) or as shown in FIG.
Japanese Unexamined Patent Application Publication No. 826 (hereinafter referred to as "Conventional Example 2") is known.

As shown in FIG. 4, the conventional example 1 has two sets of left and right bearing bosses 36-3 formed separately from the cylinder head 14 in the rocker arm chamber 20a of the cylinder head 14.
7, each of the bearing bosses 36 and 37 is configured to pivotally support each of the pivotal supports 13a of the left and right rocker arms 13 with a rocker shaft 38. The output arm 13c of each rocker arm 13 projects from the inclined upper side of each pivot 13a toward the left and right sides, and the input arm 13b symmetrically moves from the pivot 13a toward the inside between the rocker shafts. It is configured to protrude.

In prior art example 2, as shown in FIG. 5, support bearing seats 37a and 37b formed integrally with a cylinder head 14 are provided in a rocker arm chamber 20a of an inclined overhead engine, and a pair of right and left rocker arms 13 and 13 is pivotally supported by a single rocker shaft 38, and seating portions 38a and 38b are formed at both ends of the rocker shaft 38.
38b are fixed to the left and right support bearing seats 37a and 37b with fixing bolts 3
It is configured to be fixed at 0.

[0005]

In the prior art 1, since the front, rear, left and right bearing bosses 36 and 37 are formed separately from the cylinder head 14, the number of parts increases and the assembling and maintenance are convenient. Decrease. In addition, since the input arms 13b are protruded symmetrically from the pivots 13a toward the inside between the support shafts, the support shafts are used to avoid interference between the left and right input arms 13b. It is necessary to set the distance between the 38 and 38 large, and the valve operating mechanism and the rocker arm chamber 20a that accommodates the valve operating mechanism,
As a result, the cylinder head 14 becomes large.

On the other hand, in the conventional example 2, a pair of right and left rocker arms 13 is pivotally supported by a single rocker shaft 38, and seat portions 38 formed at both ends of the rocker shaft 38 are provided.
The inconvenience can be solved by fixing the a. 38b to the left and right support bearing seats 37a and 37b with the fixing bolts 30. However, in an overhead valve engine having a pent roof type combustion chamber, the intake and exhaust valve shafts have a V-shape. Will be provided,
It cannot be applied to this type of engine.

The present invention has been made in view of such circumstances, and while each rocker arm is pivotally supported by an individual rocker shaft, the convenience of assembly and maintenance is enhanced, the distance between the rocker shafts is reduced, and a cylinder is provided. It is a technical object to reduce the size of a head and a head cover.

[0008]

The invention described in claim 1 has the following basic configuration. That is, two rocker shafts 38 are juxtaposed in the rocker arm chamber 20a of the inclined overhead valve engine E having the pent roof type combustion chamber 17 so that the rocker arms 13 are pivotally supported.
Is configured to pivot.

According to a first aspect of the present invention, there is provided a rocker arm supporting device having the above-described basic configuration, which has the following characteristic configuration. That is, in the rocker arm chamber 20a, support bearing seats 37a and 37b integrally formed with the cylinder head 14 are provided on the front, rear, left and right, and seat portions 38a and 38b are formed at both ends of each rocker shaft 38, and the seat portions 38a and 38b are formed. The above bearing seat 37a
・ Fix to 37b with the fixing bolt 30. Among the support bearing seats 37a, 37b, 37a, 37b, a pair of left and right support bearing seats 37a, 37a on the inclined upper side are arranged inside the respective valve spring receiving seats 33, 33, and each intake / exhaust valve shaft 15 It is characterized in that it is formed in a substantially V shape along the state 16 (see FIGS. 1A and 1B).

According to a second aspect of the present invention, in the rocker arm spindle device according to the first aspect, the input arms 13b of the left and right rocker arms 13 are directed inward from the respective pivotal support portions 13a between the rocker shafts 38. And is protruded so as to be shifted back and forth [FIG. 1 (A)].
reference〕.

[0011]

According to the present invention, the following functions and effects can be obtained. (A) According to the invention described in claim 1, in the rocker arm support device having the basic configuration, support bearing seats 37a and 37b formed integrally with the cylinder head 14 are provided in the rocker arm chamber 20a at front, rear, left and right. Since the seating portions 38a and 38b are formed at both ends of the rocker shaft 38, and the seating portions 38a and 38b are fixed to the support bearing seats 37a and 37b with the fixing bolt 30, the number of parts is reduced as in the second conventional example. The convenience of assembly and maintenance can be improved.

(B) According to the first aspect of the present invention, the pair of left and right support bearing seats 37a on the inclined upper side are disposed inside the respective valve spring receiving seats 33.
Since they are formed in a substantially V-shape along the respective intake / exhaust valve shafts 15 and 16, each support seat 37 a is prevented from interfering with the left and right valve springs 31, and each rocker arm 13 is connected to an individual rocker shaft 38. The distance between the rocker shafts is reduced while being pivotally supported at 38, so that the valve operating mechanism can be made compact, and the rocker arm chamber 20a for accommodating the valve operating mechanism, and hence the cylinder head and head cover, can be made compact.

(C) According to the second aspect of the present invention, the input arms 13b of the left and right rocker arms 13 are connected to each pivot 1
3a, it is shifted inward and forward toward the inside between the rocker shafts 38, 38. In addition to the above-mentioned effects (a) and (b), the distance between the shafts can be reduced while avoiding interference between the left and right input arms 13b. It can be set smaller.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention. 1A is a plan view of the cylinder head viewed from an inclined side, FIG. 1B is a vertical cross-sectional view taken along line BB in FIG. 1A, and FIG. 1C is FIG. 4) is a vertical sectional view taken along line CC in FIG. FIG. 2 is a sectional view taken along line AA in FIG.
FIG. 3 is a vertical sectional front view of an air-cooled single cylinder inclined overhead valve engine to which the present invention is applied.

First, the outline of the tilt type overhead valve engine will be briefly described. This tilt type overhead valve engine E
As shown in FIG. 3, the crankcase 42 and the cylinder block 19 are integrally formed, and the cylinder block 19
, A cylinder head 14 is assembled, and a head cover 20 is assembled to the cylinder head 14.
The crankshaft 23 is located on the upper side inclining in the crank chamber 42a.
On the lower side of the inclination, the valve gear cam shafts 9 are provided so as to be parallel to each other, and the drive gear 34 meshes the valve gear cam gear 26, and the drive gear 34
The governor gear 28 is meshed with the crankshaft 23 to drive the valve operating camshaft 9 and the governor 32 with the crankshaft 23.

As shown in FIGS. 1A, 2 and 3,
The valve cam shaft 9, the left and right tappets 10, 10 and the push rods 11, 11 are disposed on the lower side of the cylinder block 19, and the rocker arms 13, 13 are arranged side by side in the rocker arm chamber 20a. . As shown in FIG. 3, the governor 32 is disposed on the upper side inclining in the crank chamber 42 a, the fuel tank 29 is disposed above the crankcase 42, and the air cleaner 49 is not shown above the cylinder head 14. An exhaust muffler is arranged.

FIG. 1B shows the cylinder head 14.
As shown in FIG. 2, a pent roof type combustion chamber 17 is formed so as to be recessed, and a pair of left and right intake valve ports 3 and an exhaust valve port 4 are opened on the surface of the cylinder head 14 facing the combustion chamber. An intake port 1 and an exhaust port 2 are respectively led to the right and left from the exhaust port 3 and the exhaust valve port 4. And the combustion chamber 17
One intake valve 5 and one exhaust valve 6 are provided on the left and right, respectively, and their respective valve shafts 15 and 16 are arranged so as to form a V-shape. The output arms 13c of the left and right rocker arms 13 are in contact with the upper ends of the left and right intake / exhaust valve shafts 15 and 16, and the input arms 13b of the respective rocker arms 13 are in contact with the upper ends of the left and right push rods 11. I have.
The intake and exhaust valves 5 and 6 are urged toward the valve closing side by valve springs 31 and 31.

As shown in FIGS. 1A and 1C and FIG.
At an intermediate position between the intake valve port 3 and the exhaust valve port 4, the insertion port 21 of the ignition plug 21
a is open. The ignition plug 21 is inserted into the insertion port 21 a, and its electrode portion is arranged facing the center of the combustion chamber 17. As shown in FIG. 1A, the cylinder block 19 and the cylinder head 14 are provided with a communication hole 35 for an oil mist that communicates the crank chamber 42a with the rocker arm chamber 20a. The intake valve shaft insertion hole 15a in the chamber 20a
Is located on the inclined side in the vicinity of. This is intended to allow the oil mist introduced from the crank chamber 42a into the rocker arm chamber 20a to effectively fall down to the valve operating mechanism.

As shown in FIGS. 1A to 1C, support bearing seats 37a, 37b and 37a are formed in the rocker arm chamber 20a integrally with the cylinder head 14 and flush with the receiving seat 46 of the head cover 20. 37b are provided on the front, rear, left and right, and a pair of left and right support bearing seats 37 on the inclined upper side among them are provided.
The a and 37a are arranged inside the respective valve spring receiving seats 33 and are formed in a substantially V shape along the intake and exhaust valve shafts 15 and 16. This is intended to reduce the distance between the rocker shafts and to reduce the size of the valve operating mechanism and the rocker arm chamber 20a for accommodating the valve operating mechanism, and hence the cylinder head and the head cover.

As shown in FIG. 1 (A), each rocker arm 13 is shifted back and forth inward between the rocker shafts 38 and 38 from the lower pivotal side of the pivot 13a. Each of the rocker arms 13b comprises a projecting input arm 13b, and an output arm 13c extending in a direction opposite to the input arm 13b from the inclined upper side of the pivotal support 13a. It is configured to pivotally support thirteen pivot portions 13a. This is intended to further reduce the shaft interval while avoiding interference between the left and right input arms 13b.

At both ends of the rocker shafts 38, seat portions 38a, 38b are formed, and these seat portions 38a, 38b are directly fixed to the support bearing seats 37a, 37b with fixing bolts 36. This configuration is intended to facilitate the assembly and maintenance while reducing the cost by omitting the bearing mechanism by the bearing. The receiving seats 37 a and 37 b are formed at the same height as the receiving seat 46 of the head cover 20. This is in consideration of the easiness of processing the receiving seats 46, 37a, and 37b.

As shown in FIG. 1A, a lubricating oil shaft introduction hole 43 is formed in the upper end surface of the pivotal support 13a of each rocker arm 13 on the inclined upper side. According to the above configuration,
The oil mist introduced into the rocker arm chamber 20a falls down on the inclined side of the pivot 13a, and lubricating oil is introduced into the pivot 13a through the shaft introduction hole 43, thereby effectively lubricating the pivot 13a. This makes rocker arm 1
The lubrication performance can be maintained high even when the third pivot portion 13a has a trunk length.

Each rocker shaft 38 is shown in FIG.
As shown in FIG. 7, the diameter of the intermediate portion in the axial direction is small, and an oil reservoir 38c is formed in the pivotal support 13a of each rocker arm 13. This is intended to store the lubricating oil introduced into the pivot 13a through the shaft introduction hole 43 into the oil reservoir 38c and to lubricate the pivot 13a more reliably. Retaining rings 39 are attached to both ends of the rocker shaft 38 to prevent falling off.

As shown in FIG. 1C, the inclined return groove 25
Is connected to a lower bottom wall portion 45 formed in the shape of a paragraph in the rocker arm chamber 20a, and an insertion hole 11b of the push rod 11 is opened in the lower bottom wall portion 45. As a result, the lubricating oil in the rocker arm chamber 20a returns from the inclined return groove 25 to the crank chamber 42a via the insertion hole 11b of the push rod 11.

[Brief description of the drawings]

FIG. 1A shows a cylinder head according to an embodiment of the present invention, FIG. 1A is a plan view of the cylinder head viewed from an inclined side, and FIG. 1 (C) is a vertical sectional view taken along line CC in FIG. 1 (A).

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a vertical sectional front view of an air-cooled single-cylinder tilted overhead valve engine to which the present invention is applied.

FIG. 4 is a diagram corresponding to FIG. 1A of a cylinder head according to Conventional Example 1.

5 shows a cylinder head according to Conventional Example 2, and FIG.
5A is a diagram corresponding to FIG. 1A, and FIG. 5B is a vertical cross-sectional view taken along line BB in FIG. 5A.

[Explanation of symbols]

13: rocker arm, 13a: rocker arm pivot,
13b: input arm, 14: cylinder head, 15.1
6 ... intake and exhaust valve shaft, 17 ... pent roof type combustion chamber, 20a
... rocker arm chamber, 30 ... fixing bolt, 33 ... valve spring receiving seat, 37a / 37b ... support bearing seat, 38 ... rocker shaft, 38a / 38b ... rocker shaft seating portion, E ... inclined type overhead valve engine.

Claims (2)

[Claims] 1. A rocker arm chamber (20) of an inclined overhead valve engine (E) having a pent roof combustion chamber (17).
a), two rocker shafts (38, 38) are juxtaposed to form a pivot (13a, 1) of each rocker arm (13, 13).
3a) a pivot device for a rocker arm configured to pivotally support the cylinder head (1) in the rocker arm chamber (20a).
Supporting seats (37a, 37b) integrally formed with the rocker shaft (38) are provided on both ends of the rocker shaft (38), and seating portions (38a, 38b) are formed at both ends of the rocker shaft (38).
8a and 38b) are fixed to the support bearing seats (37a and 37b) with fixing bolts (30). Of the support bearing seats (37a and 37b) and (37a and 37b), a pair of left and right support bearings on the inclined upper side. Seat (37a ・ 37
a) is disposed inside each valve spring receiving seat (33, 33), and is formed in a substantially V shape along each intake / exhaust valve axis (15, 16). Shaft device. 2. The rocker arm support device according to claim 1, wherein the input arms (13b) of the left and right rocker arms (13) are connected to each other.
Rocker shaft (38/38) from each pivot (13a)
A rocker arm support device, which is provided so as to be shifted forward and backward toward the inside between the two.