JPH045686Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spring support device for supporting a spring for an intake/exhaust valve in an internal combustion engine against a cylinder head.

[Conventional technology]

Since the intake/exhaust valves in an internal combustion engine are configured to rotate as the intake/exhaust valves open and close, the springs that hold the intake/exhaust valves closed also rotate as the intake/exhaust valves rotate.

Therefore, if the springs for the intake and exhaust valves are supported in direct contact with the cylinder head made of a relatively soft material such as aluminum alloy or cast iron, the springs may bite into the cylinder head. This spring, in turn, impedes the rotation of the intake and exhaust valves.

Therefore, in the past, a spring made of a metal plate was used between the spring for the intake/exhaust valve and the cylinder head, as described in, for example, Japanese Utility Model Application Publication No. 57-137706 or Japanese Utility Model Application No. 59-13618. By inserting the seat, the intake/exhaust valve springs are prevented from digging into the cylinder head.

[The problem that the idea attempts to solve]

However, when a spring seat is inserted between the intake/exhaust valve spring and the cylinder head, the spring seat will stick to the cylinder head due to the large spring force of the intake/exhaust valve spring. On the other hand, the intake/exhaust valve spring contacts the spring seat in a narrow area, and slides against the spring seat in this narrow contact area, thereby causing the spring to come into contact with the spring seat. The spring seats had to be replaced frequently because the rotation of the intake and exhaust valves was hindered by wear.

Furthermore, Japanese Utility Model Publication No. 50-14015 proposes providing a spring seat made of synthetic resin with a low coefficient of friction on one end surface of the spring for intake and exhaust valves.
Making the spring seat that supports the large spring force in the intake/exhaust valve springs made of synthetic resin is
Of the synthetic resin spring sheet, the suction and
Since local dents and sagging occur in the area where the exhaust valve spring comes into contact, the durability of the spring seat itself is much lower than that of the metal plate spring seat. Since it is made of synthetic resin, the manufacturing cost increases considerably.

The present invention provides a spring receiving device in which the durability of the spring seat is improved when the spring seat is inserted between the intake/exhaust valve spring and the cylinder head.

[Means to solve the problem]

To achieve this object, the present invention provides a spring support device for intake/exhaust valves in which a spring seat is inserted between a spring for the intake/exhaust valve and a cylinder head. Composed of two spring sheets,
The structure is such that a hardened layer is formed by carburizing and quenching only on the surface of one of the two spring seats that is in contact with the cylinder head.

[Functions and effects of the idea]

With this structure, one spring seat, which has a hardened layer formed by carburizing and quenching on its surface, is pressed against a relatively soft cylinder head made of aluminum alloy or cast iron by the large spring force of the intake/exhaust valve spring. By doing so, the cylinder head is brought into close contact with the cylinder head in a non-slip state or in a state with little slippage.

On the other hand, the other spring seat in contact with the intake/exhaust valve spring does not have a hardened layer formed by carburizing and quenching, so the other spring seat is hardened.・As the exhaust valve spring bites into itself,
It will be locked in a non-slip state or a state with little slippage relative to the intake/exhaust valve springs.

In other words, one of the two spring seats that contacts the cylinder head is attached to the cylinder head side, and the other spring seat that is in contact with the intake/exhaust valve spring is attached to the intake/exhaust valve spring. As the intake/exhaust valves rotate, the other spring seat in contact with the spring for the intake/exhaust valves will slide against the one spring seat in contact with the cylinder head, causing the intake/exhaust valves to Since the spring force of the spring can be distributed over a wide contact area between both spring seats, there is no wear caused by the rotation of the intake/exhaust valve at the contact area between the spring seat and the intake/exhaust valve spring, and the spring seat This not only reduces the wear that occurs at the contact area between the spring seat and the cylinder head, but also reduces the wear that occurs at the contact area between both spring seats.

Therefore, according to the present invention, the suction/exhaust valves can be rotated smoothly, and the durability of the spring seat inserted between the suction/exhaust valve spring and the cylinder head can be improved. The frequency of replacement can be reduced, and since the two spring seats are both made of carbon steel sheets, it is only necessary to form a hardened layer on one of them by carburizing and quenching, so it is possible to reduce the frequency of replacement. It also has the advantage that it can be provided at considerably lower cost than when using a spring seat.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 indicates a cylinder head made of aluminum alloy or cast iron, reference numeral 2 indicates an intake valve or exhaust valve, and reference numeral 3 indicates the intake valve or exhaust valve. The springs for the intake and exhaust valves are shown to keep the valves normally closed.

Further, the reference numeral 4 in the figure indicates the spring 3 for the intake/exhaust valve.
A spring seat inserted between the cylinder head 1 and the cylinder head 1 is shown, and the spring seat 4 is composed of two spring seats 4a and 4b. Made of carbon steel plate such as cold rolled steel plate (SPCC).

Then, one of the spring seats 4a and 4b, which is in contact with the cylinder head 1, is subjected to a hardening treatment such as carburizing and quenching to form a hardened layer on its surface. - The other spring seat 4b in contact with the exhaust valve spring 3 is not subjected to hardening treatment such as carburizing and hardening.

In this way, one spring seat 4a, whose surface has been hardened by hardening such as carburizing, is made of a comparatively aluminum alloy or cast iron material by the large spring force of the intake/exhaust valve spring 3. By being pressed against the soft cylinder head 1, the other spring seat 4b, which is in contact with the intake/exhaust valve spring 3, is in close contact with the cylinder head 1 in a non-slip state or in a state with little slip. Because the hardening is not applied, the hardened intake/exhaust valve spring 3 bites into the other spring seat, causing it to slip against the intake/exhaust valve spring. Therefore, as the intake valve or exhaust valve 2 rotates, both spring seats 4a and 4b apply a large spring force in the intake/exhaust valve spring 3. This results in relative sliding in a dispersed state.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a longitudinal sectional front view and FIG. 2 being an exploded view of the spring seat. 1... Cylinder head, 2... Intake valve or exhaust valve, 3... Spring for intake/exhaust valves, 4... Spring seat, 4a... One spring seat, 4b
...The other spring seat.

Claims (1)

[Scope of utility model registration request] In a spring support device for intake/exhaust valves in which a spring seat is interposed between a spring for the intake/exhaust valve and a cylinder head, the spring seat is constituted by two spring seats made of carbon steel plates. A spring bearing device for an intake/exhaust valve in an internal combustion engine, characterized in that a hardened layer is formed by carburizing and quenching only on the surface of one of the two spring seats that contacts the cylinder head.