JP2945910B2 - Manufacturing method of tappet used for valve train - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a manufacturing method of the tappet for use in direct acting type valve operating mechanism.

[0002]

2. Description of the Related Art In recent years, with the demand for higher rotation and higher output of an engine, further reduction in the weight of a valve train has been demanded. Accordingly, tappet bodies other than tappet shims used in direct-acting valve trains are also shifting from conventional iron to aluminum alloy.

[0003]

However, the tappet body made of an aluminum alloy has a drawback that strength and rigidity are inferior to those of an iron tappet body, and in particular, the cylindrical portion of the tappet body supported by a cylinder head. The outer peripheral surface of the cylinder and the contact surface with the cylinder head support hole have impact resistance,
Wear resistance is required.

[0004] In order to meet the above-mentioned requirements, a metal having high hardness has been sprayed or quenched on the outer peripheral surface of the cylindrical portion of the tappet main body, so that the surface layer has been satisfied. After or after quenching, the outer peripheral surface of the tappet main body cylindrical part must be modified again, in order to correct the thermal sprayed layer or the quench hardened layer,
There is a problem that unevenness occurs in the thickness and accuracy is deteriorated. In addition, there are problems in that the manufacturing process is diversified and the cost is increased.

The present invention has been made to solve the above-mentioned problems, and has a tubular body fitted to an outer peripheral surface of a tappet body, particularly, a cylindrical portion without performing operations such as thermal spraying and quenching. intensity in the outer peripheral surface of the cylindrical portion, the Tape' bets which can increase the rigidity, soup produced easily and at low cost
It is an object of the present invention to provide a method for manufacturing such a tappet .

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a cylindrical upper mold and a fitting of the upper mold.
In the lower die of a press device consisting of a lower die with a fitting hole
At the approximate center of the bottom of the fitting hole, the outer diameter is smaller than the inner diameter of the fitting hole.
And a tappet book is formed on the top of the raised portion.
Material made of aluminum or its alloy for body forming
And harder and slightly elastically deformed than the material
Made of possible material and outer diameter is smaller than inner diameter of fitting hole
The cylindrical body was inserted between the fitting hole and the raised portion.
Then press the material with the upper die to form the tappet body.
At the same time as the shape, the cylindrical body is expanded by elastic deformation.
And fit it to the outer peripheral surface of the cylindrical portion of the tappet body.
Features.

[0007]

According to the tappet manufacturing method of the present invention,
And the outside of the cylindrical part of the tappet body by one press
Fit a cylinder that is harder than aluminum or its alloy on the peripheral surface
You can wear it.

[0008]

FIG. 1 (1) shows a tape manufactured according to the present invention.
Is shown. The tappet (1) is fitted to a tappet body (2) composed of a cylindrical portion (3) and a disc portion (4) made of aluminum or its alloy, and an outer peripheral surface (3a) of the cylindrical portion (3). Harder than aluminum, etc.
It comprises a cylindrical body (5) made of molybdenum steel and a steel shim (6) mounted on the disk part (4).

The cylindrical portion (3) of the tappet body (2) is slidably fitted in a guide hole formed in a cylinder head (not shown). At a substantially central portion of the inner surface of the disk portion (4), a contact surface (7) with which a stem end of an engine valve (not shown) abuts is protruded downward. The cylindrical body (5) has a thickness of about 0.1 mm, and its upper and lower ends are open, and has elastic contraction at least at room temperature.

The shim (6) is rotatably fitted in a concave portion (12) formed by a disc portion (4) and an upper end portion of a cylindrical portion (3) protruding above the disc portion (4). It is in contact with the cam.

In the tappet (1), since the tubular body (5) is fitted to the cylindrical portion (3) of the tappet body (2) in an elastically contracted state at room temperature, it is exposed to high temperature, for example. Even if the cylinder (5) does not fall out of the cylinder (3) and the guide hole of the cylinder head and the cylinder (5) are in sliding contact with each other, the cylinder (5) can prevent the cylinder (3) from sliding. Since the strength and rigidity of the outer peripheral surface are enhanced, wear of the sliding contact surface is significantly reduced.

Next, the tappet will be described with reference to FIGS.
A method for manufacturing the main body (2) will be described. (13) in the figure is not shown.
The lower die, which forms part of the press machine, and (14) is the upper die
The upper mold (14) exits through the fitting hole (15) provided in the lower mold (13).
It is immersible.

The lower die (13) has a substantially central portion at the bottom of the fitting hole (15).
Is a cylindrical ridge with an outer diameter smaller than the inner diameter of the fitting hole (15).
A raised portion (17) is provided upright. The side (17a) of the ridge (17)
As a tapered surface that gradually tapers as it goes upward
There is a tape between the tapered surface and the lower die wall (13a).
The cylindrical hollow portion (19) forming the cylindrical portion (3) of the main body (2)
Is formed. The corners (17c) of the ridges (17) are rounded
It is formed so that the molding material can easily enter. (1
8) is a concave portion provided substantially at the center of the top portion (17b) of the raised portion (17).
It is. (20) is a material for forming the tappet body (2).
You.

The top (17b) of the ridge (17) is made of aluminum.
Material (20) and place the upper end of the cylinder (5) on the material (20).
Protrude slightly from the upper end, and the fitting hole (15)
(17), and the lower end of the cylinder (5) abuts on the bottom (16).
It is located in the state where it was made. Then, from the state shown in FIG.
Lower the upper mold (14) into the fitting hole (15) as shown by the arrow, and
0) to stop at a predetermined position shown in FIG.

Then, the material (20) is recessed almost simultaneously with the pressing.
(18) and into the hollow part (19), and remove the tappet body (2).
The cylindrical part (3), the disk part (4) and the disk part (4)
The contact surface (7) that contacts the valve stem end is formed on the side
You.

At this time, the cylinder (5) is laterally almost simultaneously with the press.
The diameter is forcibly expanded by elastic deformation. That is,
The cylinder (5) is in a state of being fitted to the cylinder (3),
(5) does not occur. Then, in a similar process
What is necessary is just to shape a tappet main body.

According to the present invention, thermal spraying, quenching, etc.
And easily fit the cylindrical body to the cylindrical portion (3) of the tappet body (2)
And its strength and rigidity can be increased.
Further, the manufacturing process is shortened, and the manufacturing cost is reduced.

Next, another tappet (1) which can be manufactured according to the present invention will be described with reference to FIGS. The same members as those of the above-described tappet (1) are denoted by the same reference numerals, and detailed description will be omitted.

In the tappet (1) shown in FIG. 4, the upper surface (3b) of the cylindrical portion (3) of the tappet body (2) is the same as that shown in the first embodiment having an annular wear resistance. Material (Chrome
Molybdenum steel, about 0.1 mm thick) is covered with an annular inward piece (8) connected to the cylinder (5). That is, when exchanging the shim (6) indicated by the imaginary line using a tool,
The upper surface (3b) of the cylindrical portion of the tappet body (2) can be prevented from being damaged by the tool.

The tappet (1) shown in FIG. 5 has elasticity shrinkage at least at room temperature, and is vertically shorter than the outer peripheral surface of the cylindrical portion (3) (9) (chromium-molybdenum steel, thickness: About 0.1
mm) is fitted to a substantially central portion of the outer peripheral surface (3a) of the cylindrical portion (3) of the tappet body (2).

The tappet (1) shown in FIG.
It is characterized in that at least two cylinders (10) having elastic contractility at room temperature are fitted to the upper and lower portions of the outer peripheral surface (3a) of the cylindrical portion (3) of (2).

In the above two tappets, the use of the cylinders (9) and (10) can be remarkably reduced by fitting the cylinders (9) and (10) at places where wear particularly occurs. The manufacturing cost of the tappet (1) is reduced. In addition, the strength and rigidity of the fitting portion are increased. Further, since the tubular bodies (9) and (10) are fitted in a state of being elastically contracted, even if the tappet body (2) is contracted in a cold region, the tubular bodies (9) and (10) are fitted to the tappet body ( There is no escape from 2).

In the tappet (1) shown in FIG. 7, not only the outer peripheral surface (3a) and upper surface (3b) of the cylindrical portion (3) of the tappet body (2) but also the inner surface of the recess (12). That is, the upper inner surface (3c) of the cylindrical portion (3) and the bottom surface of the recess (12), that is, the upper surface (4a) of the disk portion (4) are also integrally covered with chromium-molybdenum steel.

The shim (6) has a concave portion (12) composed of a disk portion (4) and an upper end portion of a cylindrical portion (3) projecting upward.
And is in contact with a rotating cam (not shown), so that the lower surface of the shim (6a), the upper surface of the disc portion (4a) and the peripheral surface of the shim (6
b) and the upper inner surface (3c) of the cylindrical part (3) always contact
Since the wear is likely to occur due to the rotation of (6), the first surface (4a) of the disk portion of the main body and the first inner surface (3c) of the upper portion of the cylindrical portion (3) are attached.
By integrally covering with the same material as the cylinder (5) shown in the embodiment, the strength and rigidity are increased, and the wear of each member can be significantly reduced.

[0025]

According to the present invention, easy and low-cost manufacturing is possible.
Depending on the manufacturing method, the strength and rigidity of the cylinder
Long product life, which can reduce wear on the contact surface with the head
A tappet body can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a tappet manufactured according to the present invention .

FIG. 2 is a longitudinal sectional view of a tappet body of the present invention before molding.

FIG. 3 is a longitudinal sectional view of the same after the tappet body is formed.

FIG. 4 is a longitudinal sectional view of another tappet manufactured according to the present invention .

FIG. 5 is a longitudinal sectional view of yet another tappet manufactured according to the present invention .

FIG. 6 is a longitudinal sectional view of yet another tappet manufactured according to the present invention .

FIG. 7 is a longitudinal sectional view of yet another tappet manufactured according to the present invention .

[Explanation of symbols]

 (1) Tappet (2) Tappet body (3) Cylindrical portion (3a) Outer peripheral surface (3b) Upper surface (3c) Upper inner surface (4) Disk portion (4a) Upper surface (5) Cylindrical body (6) Shim (7 (8) Inward facing piece (9) (10) Cylindrical body (12) Recess (13) Lower die (13a) Wall surface (14) Upper die (15) Fitting hole (16) Bottom part (17) Raised part (17a) Side (17b) Top (17c) Corner (18) Concave (19) Hollow (20) Material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-170710 (JP, A) JP-A-58-185913 (JP, A) JP-A-1-315607 (JP, A) JP-A 63-170913 9606 (JP, A) Japanese Utility Model 63-174508 (JP, U) Japanese Utility Model Hei 4-105903 (JP, U) Japanese Utility Model Utility Model 1-97003 (JP, U) (58) Field surveyed (Int. ⁶ , DB name) F01L 1/14

Claims (1)

(57) [Claims] 1. A cylindrical upper mold and a fitting to which the upper mold is fitted.
In the lower die of the press device consisting of the lower die having a hole
At the approximate center of the bottom of the fitting hole, make the outer diameter smaller than the inner diameter of the fitting hole.
And a tappet body is formed at the top of the raised portion.
Place a material made of aluminum or its alloy for forming
And it is harder and slightly elastically deformable
Material with a smaller outer diameter than the inner diameter of the fitting hole
The inserted cylindrical body is inserted between the fitting hole and the raised portion, and then
Then press the material with the upper mold to form the tappet body
At about the same time, the cylindrical body is expanded by elastic deformation.
To be fitted on the outer peripheral surface of the cylindrical portion of the tappet body.
A method of manufacturing a tappet used for a valve operating mechanism.