JPH0752438Y2 - Disc spring assembly - Google Patents

Description

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

(Prior Art) FIG. 4 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 drawing, the bolt 5 is used for the cylinder head 2 and the manifold 4.
It is generally arranged so as to be inclined with respect to the mounting surface of the.

(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 4 to move the cylinder head 2 in the direction of expanding the 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, the conventional structure cannot elastically absorb the thermal deformation, causing cracks in the member or deterioration of the sealing function, resulting in leakage of gas or cooling water. There was a problem such as causing. In order to solve such a problem, it is considered to use a disc spring instead of the flat washer 6 interposed between the head 5a of the bolt 5 and the manifold 4. Moreover, as shown in FIG. 5, the compression deflection amount δ of the disc spring due to the load P is much larger in the case where two disc springs are used (A) than in the case where one disc spring is used (A).
Since the amount of bending increases as the number of individual use (C) increases, an appropriate number is selected and a disc spring is used to absorb the thermal deformation. As an actual implementation of this idea, as shown in FIG. 6, three disc springs 7 are stacked so as to face each other, and these disc springs are housed in a holder 8 of a cylindrical body whose both ends are narrowed. There is a disc spring assembly. A hole 8c having the same diameter as the inner diameter of the disc spring 7 is formed in the end surface 8a of the holder 8 that is in contact with the manifold side, and a hole having a size that does not interfere with the bolt head or the nut is formed in the opposite end surface 8b. There is. However, in this structure, the holder 8 has to be housed in the disc spring 7 and drawn, which is time-consuming and costly, and the holder 8 is thin, so that the holder surface is closer to the seat surface (8a). There is a problem that the surface pressure distribution becomes uneven and the outer diameter becomes large, which is disadvantageous in space. Therefore, as shown in FIG. 7, a concave portion 9a is formed in the upper surface inner diameter portion of the uppermost disc spring 9 among the three disc springs 9, 10 and 10, and the thick flat washer 11 disposed at the lowest position is formed. A recessed portion 11a is bored in the inner surface of the lower surface, one notch is provided along one generatrix to allow expansion and contraction in the radial direction, and a cylindrical elastic holder 12 having both ends thereof expanded is prepared in advance, Disc springs 9, 10, 10 and plain washers 1 stacked as shown
A disc spring assembly is conceivable in which the holder 12 is inserted into the inside of 1 while being sandwiched between the fingers while being reduced, and after the insertion, the finger pressure is released to assemble. However, in this structure, the depth of the recess 9a of the uppermost disc spring 9 cannot be set sufficiently, and the worker may not notice it even if the flat washer 11 is inadvertently placed in the upper position during assembly. However, such a wrong assembly naturally causes a problem that the surface pressure distribution on the bearing surface side becomes uneven.

(Means for Solving the Problems) The present invention has been made in order to solve the above-mentioned problems of the prior art all at once, and both sides of disc springs (hereinafter simply referred to as disc spring groups) stacked facing each other. A flat washer is installed in the flat washer, and an elastic holder having a hollow part through which the bolt can be inserted is inserted into the disc spring group and the insides of the flat washers on both sides. Alternatively, the recesses formed in the surfaces facing the nut and the object to be tightened are expanded, and the length of the holder is the total length of the disc spring assembly less the total compression deflection amount than the free length of the disc spring assembly. It is characterized by being shorter than the length.

(Function) Since flat washers are arranged on both sides, either flat washer may be placed on the bottom. In the case of bolts implanted in the cylinder head, this bolt does not take into consideration the direction of the disc spring assembly. Then, the nut may be screwed onto the above bolt, and then tightened with a specified torque. Even if the disc spring groups are tightened until they come into close contact with each other, the holder is prevented from interfering with each other. The same applies to the case where a push bolt is used in place of the stud, and is screwed into a screw hole formed in the cylinder head.

(Example) Hereinafter, the illustrated example will be described in detail. In FIG. 1, the disc spring assembly 20 is a flat washer 21, 21 of the same shape.
And the spring holders 22 and 22 arranged so as to face each other and an elastic holder for preventing the flat washers and the disk springs from coming off from each other.
It consists of 23 and. FIG. 1 shows a case where a so-called stud bolt 25, which is planted in a cylinder head 24 as a tightening body, is tightened with an intake manifold 26, which is a tightened body, by a nut 27 via a disc spring assembly 20. Moreover, the disc spring assembly 20 shows a state in which the free length L in which no load is applied remains. The flat washer 21 is provided with a circular recess 28 concentric with the hole, and the thickness t has such a thickness that it is not deformed even when a predetermined load is applied. In this case, the disc spring group has shown an example in which two disc springs are used and face each other and are stacked, but of course the number is not limited to two and may be three as shown in the prior art. Needless to say. An example of the structure of the holder 23 will be described with reference to FIG. In this drawing, the holder 23 is made of, for example, a thin plate having elasticity, and after forming both end edges of a rectangular plate into a tooth shape that meshes with each other, the holder is wound into a cylindrical body, and further, both end portions of this cylindrical body are Expand and flange part 2
It is formed by forming 9,29. 1 and 2 both show the free state of the holder 23. In this state, the inner diameter d is larger than the outer diameter of the bolt 25, and the outer diameter of the flange 29 is larger than the inner diameter of the recess 28 of the flat washer. Small diameter, holder 23
The outer diameter D of the abdomen is smaller than the hole diameters of the flat washer 21 and the disc spring 22. The total length H of the holder 23 is the disc spring assembly.
It is set shorter than the length obtained by subtracting the total compression deflection amount of the disc spring group from the free length L of 20. That is, when the holder 23 is free, the outside of the bolt 25, the flat washer 21 and the disc spring 20 are
The holder 23 does not interfere with any of the members even if the nut 27 is screwed with a normal torque without extending into the space area between the holder 23 and the inside of the holder. To set the holder 23, the abdomen of the holder 23 may be inserted by being compressed by finger pressure or an appropriate method.
If the acupressure is released after the insertion, the free state is restored by self-elasticity and the flat washers 21, 21 are hooked by the flanges 29, 29, and the disc spring assemblies 20 do not fall off or separate from each other. FIG. 3 shows a modification of the holder. In this case, legs 31 are hung from the inner diameter portion of the ring 30 at equal intervals around the circumference, and the tips of the legs 31 are expanded outward to engage with the recesses of the flat washers.

(Effect of the Invention) The disc spring assembly according to the present invention can be processed individually for each member, so that the cost can be reduced, and the surface pressure distribution on the seat surface can be reduced because the flat washer has a sufficient thickness. It is uniform and is particularly effective when the tightened body is soft such as aluminum alloy.The holder is inserted in the gap area between the flat washer and disc spring group and the bolt, so the outer diameter is small and compact. Since the plain washers are arranged on both sides in the axial direction, there is no directionality of assembly and there is no risk of misassembly. Furthermore, the holder end is expanded compared to the example shown in FIG. This has the effect that there is a sufficient margin for the depth of the recess formed in the thick flat washer with respect to the opened flange portion.

[Brief description of drawings]

1 is a sectional view of a disc spring assembly showing an embodiment of the present invention, FIG. 2 is an external perspective view showing a holder used in the above embodiment, and FIG. 3 is an external perspective view showing a modified example of the holder. FIG. 4 is a schematic view showing a supply (exhaust) air manifold mounting structure in a V-type engine to which the present invention is directed, FIG. 5 is a view showing characteristics of a disc spring, and FIGS. 6 and 7 are conventional drawings. It is sectional drawing which shows the example of a disc spring assembly. 20 ... Disc spring assembly, 21 ... Plain washer, 22 ... Disc spring, 23
… Holder, 25… Bolt, 28… Recess, 29… Flange.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F02M 35/104 F16B 39/24 A 43/00 A F16F 1/32

Claims (1)

[Scope of utility model registration request] 1. A disc spring group which is interposed between a head portion or a nut of a bolt and a body to be tightened and which is faced to each other and overlapped with each other, and flat discs which are respectively disposed on both end sides of the disc spring group. In a disc spring assembly consisting of a washer, a flat washer having recesses formed on the surfaces facing the head of the bolt or the nut and the object to be fastened, the outside of the inserted bolt and the flat washer and disc spring group. An elastic holder that extends in the region between the inner side and both ends of the flat washer and is expanded into the recess, and the length of the holder is greater than the free length of the disc spring assembly. A disc spring assembly characterized by being shorter than the length obtained by subtracting the amount of compression deflection.