JPH0225012Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is applicable to sealing parts of engines, liners, etc.
This invention relates to improvements in seal packing used in pipe joints, etc.

[Conventional technology]

Conventionally, molded products made of asbestos or a plurality of thin metal plates, such as stainless steel thin plates and brass thin plates alternately stacked one on top of the other, have been widely used as seal packings.

[Problems to be solved by the invention] Since asbestos is fibrous, it is difficult to obtain reliable airtightness, and it also has poor heat resistance, so it is not suitable for high-temperature applications (for example, above 400°C). Seal packings made of thin metal sheets have the heat resistance necessary for applications such as automobile engine gaskets, but they require forming processes such as curling to facilitate stacking the metal plates, and they also require molding processes such as curling. The installation work is also troublesome and time consuming. Moreover, in order to ensure that the overlapping surfaces of multiple thin metal plates are in close contact, it is necessary to apply a strong tightening torque, and even if sufficient tightening torque is applied, vibrations and temperature rises and falls during the use process may occur. Due to repeated use, the tightening torque tends to loosen and the airtightness between the overlapping surfaces tends to deteriorate accordingly.

The present invention has been made in order to solve the above-mentioned drawbacks of conventional seal packings.

[Means for solving the problem] The seal packing of the present invention uses a carbon steel plate as a core material, and both sides of the core material are coated with an Al-Si molten aluminum plating layer containing 1 to 15% by weight of Si, and the sealing material is bonded to the core material. It is characterized by having a continuous or discontinuous layer of Fe-Al alloy at the interface with the layer.

FIG. 1 shows an example of the seal packing of the present invention. This is a gasket used, for example, as a gasket for an automobile engine. Figure 2 shows its A-A cross section, where 1 is the carbon steel plate that is the core material, and 2 and 2 are the Al-Si molten aluminum plating layers (hereinafter referred to as "aluminum plating layers") that cover both sides of the core material. ), 3, 3 are Fe--Al alloy layers formed at the interface between the carbon steel plate 1, which is the core material, and the aluminum plating layers 2, 2. The thickness of the aluminum plating layers 2, 2 depends on the application and usage conditions of the packing, but is usually about 0.005~
It is sufficient if it is about 0.1mm.

The interface between the core steel plate 1 and the aluminum plated layers 2, 2 in the aluminized steel plate that has been hot-dipped
Fe-Al alloy layers 3, 3 exist as continuous layers,
The figure shows a state in which the material exists as an interrupted layer that has been separated by cold rolling as described later.

The seal packing of the present invention is manufactured by using a carbon steel plate as a plating original plate, and punching the steel plate into the desired shape using the Sendzimer method using a molten aluminum bath containing 1 to 15% by weight of Si. Ru. Aluminum plating with Si1~15% by weight Al-
The Si alloy is made of core material 1, aluminum plating layer 2,
This is to form Fe--Al alloys 3, 3 in just the right amount between the layers 2 and 2, which contribute to improving the sealing performance of the packing.

The Fe-Al alloy layers 3, 3 are generated by a diffusion reaction at the interface between the core material 1 and the aluminum plated layers 2, 2 in the plating process, and the formation of the alloy layer causes the core material to
The adhesion between the fastening layers 2, 2 is strengthened. Further, the alloy layers 3, 3 have a hardness of about 800 Hv, which is extremely hard compared to the hardness of the aluminum plating layers 3, 3 (about 40 to 50 Hv).

The fact that the Fe-Al alloy layers 3 and 3 are extremely hard layers and that the formation of these alloy layers strengthens the adhesion between the core material 1 and the mating layers 2 and 2 is effective in improving the sealing performance of the packing. contribute to the However, since it is an extremely hard and brittle layer, if it is produced in excess, the workability of the plated steel sheet will be significantly impaired, and it may cause cracks and peeling of the plated layers 2, 2 during forming processes such as punching. Become. Therefore, in the present invention, the aluminum plating layers 2, 2 are made of an Al-Si alloy with a Si content of 1 to 15% by weight, thereby preventing excessive diffusion reaction at the interface between the core material 1 and the plating layers 2, 2. The Fe--Al alloy layers 3, 3 are formed in just the right amount to prevent the progress and, as a result, to improve the sealing performance.
The layer thickness of the Fe-Al alloy 3,3 is approximately 2 to 7 μm
It is.

Prior to punching the molten aluminized steel plate into a package of a desired shape, a skin pass is applied at a rolling reduction rate of about 0.5 to 3% for the purpose of shape correction, etc., if necessary. This skin pass not only corrects the shape, but also improves the adhesion between the core material 1 and the aluminum plating layers 2, 2, and also eliminates the pinholes and minute imperfections in the aluminum plating layers 2, 2, thereby eliminating the crimping. The homogeneity of the layer is improved.

In addition, we use a molten aluminized steel plate that is thicker than the intended packing, and apply a rolling reduction of approximately 20.
By applying ~60% cold rolling to reduce the thickness of the packing plate to a predetermined thickness, the Fe-Al alloy layers 3, 3 at the interface between the core material 1 and the aluminum plating layers 2, 2 are separated. The continuous layer becomes an interrupted layer as shown in FIG. By dividing the Fe-Al alloy layers 3, 3, the influence on workability (cracks and peeling of the plated layer) caused by the hard and brittle layers is greatly alleviated,
Provides crack resistance and peeling resistance that can withstand heavy processing. When this cold rolling process is performed, recrystallization annealing treatment is performed to eliminate the work hardening, if desired. Due to the annealing process, the crystal grains of the core material 1 and the aluminum plating layers 2, 2 become coarser and softer, making it easier to tighten them when installing the packing. If the core material 1 itself does not require much workability, it is sufficient to recrystallize only the aluminum plated layers 2, 2 by annealing in a low temperature range (approximately 250 to 500°C). In addition, when recrystallization annealing treatment after cold rolling is performed at a relatively high temperature, the Fe-Al alloy layer 3, Since the formation of 3 is observed, if you wish to suppress the formation, add 0.005 to 0.04 nitrogen N to the carbon steel sheet that is the core material 1.
It is preferable to use one containing % by weight.

[Effect]

The seal packing of this invention has a core material made of carbon steel plate (its hardness is about Hv 110), which is soft.
It is coated with an Al-Si aluminum plating layer (Hv approx. 40-50), and an extremely hard Fe-Al alloy layer (Hv approx. 800) is interposed in a continuous or divided state at the interface. Since it has a three-layer laminated structure with significantly different resistance (resistance), the spring effect due to the tightening pressure is high and it is difficult to loosen during use. Furthermore, the tightening torque required when attaching to the seal portion may be relatively small. Moreover, since the three-layer structure has an integral bonding relationship, unlike a simple stacked structure of multiple plates, there is no overlapping surface and there is no problem of deterioration of sealing function due to gaps between layers. .

[Effect of idea]

The seal gasket of this invention has excellent airtightness and heat resistance, and compared to those made by laminating multiple thin metal plates, it does not require any troublesome manufacturing or installation time, and can provide reliable sealing with low tightening torque. It is. In addition, the seal gasket of the present invention is manufactured from a hot-dip aluminized steel plate with an inexpensive carbon steel base plate, so it is less expensive than when the gasket is made from a soft metal plate such as an aluminum plate or copper plate. In addition, since the coefficient of thermal expansion is small, sealing performance does not deteriorate due to temperature changes, and the thermal conductivity is low, so it has advantages such as being able to suppress thermal effects on adjacent members.

Therefore, the packing of the present invention can be used for automobile engines,
It is useful as a seal for various seals such as pipe joints and liners.

[Brief explanation of drawings]

Figure 1 is a plan view of the embodiment of the present invention, Figure 2 is A-
It is an A sectional view. 1...core material, 2...aluminum plating layer, 3...Fe-Al
Alloy layer.

Claims (1)

[Scope of utility model registration request] A carbon steel plate is used as a core material, both sides of which are coated with an Al-Si molten aluminum plating layer containing 1 to 15% by weight of Si, and a continuous or discontinuous layer of Fe-Al alloy is provided at the interface between the core material and the plating layer. Seal patch skin featuring.