JPH075295Y2 - Belleville spring washer bolt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a disc spring washer bolt suitable for mounting a supply / exhaust manifold of a V-type engine.

(Prior Art) FIG. 5 shows a V-type engine as a whole, and a cylinder head 2 is provided in each Y-shaped engine block 1.
Are fixed via bolts 3, and, for example, intake manifolds (hereinafter simply referred to as manifolds) 4 are attached to the left and right cylinder heads 2 via bolts 5. As shown in the figure, the bolts 5 are generally arranged so as to be inclined with respect to the mounting surface of the cylinder head 2 and the manifold 4.

(Problems to be solved by the invention) However, since the cylinder head 2 is generally made of an aluminum alloy and the manifold 4 is generally made of cast iron, a large difference in thermal expansion occurs during high load operation, and the manifold is A force is generated by which 4 moves the cylinder head 2 so as to widen its V bank. Moreover, since the mounting surfaces of both of them are inclined in an inverted V shape, the manifold 4 tends to move upward along the mounting surface. On the other hand, when the engine cools, the amount of contraction of the manifold 4 is large, so the manifold 4 tries to move downward along the mounting surface.
If such expansion and contraction are repeated, this thermal deformation cannot be elastically absorbed, causing cracks in the member or deterioration of the sealing function, resulting in leakage of gas or cooling water. The problem arises. Therefore, there is an idea that a plurality of disc springs are interposed between the bolt head and the manifold to elastically absorb thermal deformation. As shown in FIG. 6,
The compression deflection amount δ of the disc spring due to the load P is much larger when two disc springs are used (B) than when one disc spring is used (A), and more when three disc springs are used (C). Since the amount increases, it is sufficient to select an appropriate number so as to absorb the thermal deformation. An example of a concrete implementation of this idea is shown in FIG. That is, the three disc springs 7 are stacked so as to face each other, and the outer periphery thereof is housed in a cylindrical holder 8 whose both ends are narrowed. More specifically, the end surface 8a of the holder 8 which is in contact with the manifold side is formed with a hole 8c having the same diameter as the inner diameter of the disc spring 7, and the opposite end surface 8b is narrowed to such an extent that it does not interfere with the rotation of the bolt head or the nut. ing. However, in this structure, since the thickness of the holder 8 is thin, the surface pressure distribution on the end surface 8a side, which is the seat surface, becomes non-uniform, and the holder 8 is
The disc spring must be housed inside and then drawn, which is time-consuming and costly, and has a large outer diameter, which is disadvantageous in terms of space.

(Means for Solving the Problem) The present invention has been made in order to solve the above-mentioned problems of the prior art, and a state in which flat washers are arranged on one side or both sides of disc spring groups facing each other. In, the disc springs or flat washers located at both ends are formed with recesses concentric with the holes at the outer end edges, and the elastic holders inserted into the disc spring group and the flat washers are located at both ends with both ends expanded. The retaining projection that faces the concave portion of the disc spring or the flat washer and is further protruded inward is formed on the outside of the screw portion when the headed bolt whose lower part of the neck is formed with a diameter smaller than the outer diameter of the screw portion is inserted. It is characterized by being able to overcome the diameter.

(Function) For example, when a flat washer is provided on one side of the disc spring group, the holder is contracted with finger pressure or the like to reduce the diameter of the disc spring group while keeping the retaining projection in a position facing the flat washer. And the flat washer to release the finger pressure to hold the disc spring group and the plain washer as an assembly, and then insert the screw part of the headed bolt from the disc spring to resist the elasticity of the retaining projection. While continuing the insertion, the protrusion tip reaches the bottom of the neck and the flat spring washer bolt is completed. This Belleville spring flat washer bolt is prepared in the production line and is used as a composite member, for example, when the intake / exhaust manifold is attached to the cylinder head.

(Example) Hereinafter, the illustrated example will be described in detail. In FIG. 1, reference numeral 10 indicates a headed bolt, a screw portion 11 at the tip is screwed into a tightening body, for example, a cylinder head 12, and a lower neck portion 13 is formed to have a diameter smaller than the outer diameter of the screw portion 11. . The bolt 10 is provided with a flat washer disk spring assembly (hereinafter abbreviated as assembly) 15 for tightening an object to be tightened, for example, an intake manifold 14. The assembly 15 includes plain washers 16 and 16, disc springs 17 and 17, and a holder 18. The flat washer 16 is formed thick enough not to be deformed by the tightening load of the bolt 10, and has a recess 19 concentric with the bolt insertion hole. The depth of the recess 19 is set under the conditions described later. In the illustrated example, two disc springs 17 are used and are stacked so as to face each other, but the number may be three and the number is not limited at all. As shown in FIG. 2, the holder 18 is made of an elastic plate such as a spring steel plate. The opposite side edges of the holder 18 are formed with complementary tooth shapes, and after winding, both ends are expanded and expanded. Flange flanges 20, 20 are formed, and a circumferential groove 21 is further formed in the center of the abdomen. The inner diameter of the circumferential groove 21 is formed to be smaller than the outer diameter of the threaded portion of the bolt 10. The holder 18 shows a free state in both figures. In the free state, the abdomen outer diameter d does not interfere with the holes of the flat washer 16 and the disc spring 17, and the outer diameter of the flange portion 20 and the circumferential slit width. W is set to a size such that the flange portion 20 can be inserted into the holes of the flat washer 16 and the disc spring 17 when the holder 18 is reduced in diameter by applying finger pressure in the direction of closing the split. Further, the distance 1 between the flange portions is equal to the recess 1 of the flat washers 16 and 16 for holding the disc springs 17 and 17 with no load.
It is set to be equal to the distance between the bottoms of 9,19,
Moreover, the length obtained by subtracting the total compression deflection amount δ of the disc springs 17 and 17 from the free length L of the assembly 15 is the total length of the holder 18 l + 2t.
It is important to be longer.

FIG. 3 shows another embodiment of the present invention. The difference from the above-described embodiment is that the flat washer is provided on only one side instead of the three disc springs, and therefore, the holder is provided with a measure for preventing misassembly because directionality occurs. That is, in this figure, the disc spring group 30 is composed of disc springs 31, 32, 33 of the same shape facing each other, and a recess 34 concentric with the hole of the uppermost disc spring 31 is formed on the upper surface. The flat washer 35 is in contact with the lowest disc spring 33, and a recess 36 concentric with the hole is formed in the lower surface. The holder 37 is formed by cutting and raising an appropriate portion of the circumference in the generatrix direction with respect to the holder material in which the circumferential groove of the holder 18 shown in the above-mentioned embodiment is removed, and forming a projection 38 having its free end protruding inward. Is different.

(Effects of the Invention) As is apparent from the above description, the present invention separately processes the disc spring, the flat washer and the holder, reduces the holder by finger pressure or the like, and inserts it into the disc spring group and the flat washer to assemble it. Since it is assembled as a product, the productivity is good and the cost is reduced, and since the thick flat washer is brought into contact with the tightening surface, the surface pressure distribution on the seating surface side becomes uniform. Such a soft material is also effective, and since the holder is housed inside, the outer diameter is small, which is advantageous in terms of space. Furthermore, since the holder has a protrusion, it is easy to control production without separating it from the bolt, and even if the flat washer has only one side, the holder has a cut-and-raised protrusion so that the plain washer is always in contact with the tightened surface. It also has the effect of being

[Brief description of drawings]

1 and 2 are respectively an assembled sectional view showing an embodiment of the present invention and a partial sectional perspective view showing a holder, and FIGS. 3 and 4 are respectively used in another embodiment of the present invention. A sectional view showing the assembly and a partial sectional perspective view showing a modified example of the holder, FIG. 5 is a schematic view showing an intake (exhaust) gas manifold mounting structure in a V-type engine to which the present invention is directed, and FIG. 6 is a dish FIG. 7 is a diagram showing the characteristics of the spring, and FIG. 7 is a sectional view showing a conventional example. 10 ... Bolt with head, 15 ... Assembly, 16, 35 ... Plain washer, 17, 31, 32, 33… Disc spring, 18, 37… Holder, 19, 34, 36…
Recesses, 20 ... Flange that is an expanded portion, 22, 38 ... Protrusions.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Koichi Namiki 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (56) Bibliographic references Sho 61-145111 (JP, U) Sho 62-146008 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A headed bolt having a lower neck portion formed to have a diameter smaller than an outer diameter of a screw portion, a disc spring group inserted through the bolt and facing each other, and arranged on one side or both sides of the disc spring group. A flat washer and a flat spring washer and a flat spring washer having elastic holders whose both ends are expanded to hold the flat washer as an assembly. A concave portion concentric with the hole is bored on the outer end face so that the expanded portion of the elastic holder faces the concave portion, and further, the elastic holder is provided with a retaining projection protruding inward. Characteristic Belleville spring washer bolt.