JPS5989843A - Compression coil spring and method of its manufacture - Google Patents

Abstract

PURPOSE:To always obtain stable comfortableness of riding without dispersion by surrounding and covering the whole circumference of a compression coil spring body with an elastic material, and providing the elastic material with a projecting sectional configuration in an integrated form with the covering material on the lower part in expanding direction, and enabling the spring constant to be varied in accordance with the number of riders. CONSTITUTION:At the lower part, in the expanding direction, of a hollow coil spring body 6'', whose circumference is wholly covered with thermoplastic elastomer 18, a projecting sectional part 20 having a wall thickness of 2/8h for the free length of 1h, is provided in an integrated form. When the load is low, a coil spring 6', wich is interposed between an upper spring holder seat 8 fixed to the top of the rod 7 of a shock absorber 5 and a lower spring holder seat 9 fixed midway in the length of the shock absorber, shows a rebound in space of 1/8h for the free length of 1h, which, being applied in combination with the damping force of the shock absorber 5, is sufficient to absorb a shock. When the load is high, each projecting part 20 is made to have functions as a non-linear spring body, a stopper body, and as a shock absorbing body, providing sufficient buffering action against a high shock, and stable comfortableness of riding is obtained.

Description

[Detailed Description of the Invention] <Technical Classification> To give a detailed explanation as an example, the disclosed technology is a technology that can vary the spring constant of a coil spring used in combination with a shock absorber in a front suspension and a rear suspension of a vehicle such as an automobile. By dividing the final long-term high load into a low load and a high load, it improves riding comfort, provides a buffering effect as a bounce stopper during road impact loads, prevents corrosion, and increases strength. It belongs to the field of coil spring technology.

Explanation of the Claims> The invention of this application provides a shock absorber connected to each of the front and rear wheels of the vehicle and interposed between the upper spring seat and the lower spring seat. This invention relates to a helical compression coil spring and a manufacturing method thereof,
In particular, the entire circumference of the compression coil spring is covered with an elastic material such as thermoplastic elastomer (TPE), and at least one of the elastic materials in the expansion/contraction direction of the compression coil spring is integrally formed with a convex cross-section. The present invention also relates to a compression coil spring in which another coil is attached to the elastic material, and a method for manufacturing the same.

<Prior art> As is well known, in order to improve riding comfort and handling stability, the front suspension and rear suspension of a vehicle are combined with shock absorbers with damping force characteristics to ensure shock absorption. Spiral coil springs are widely used in passenger cars.

Conventionally, for example, as shown in Fig. 1, a front suspension 1 of an automobile has a wheel 2 pivoted, a shock absorber 5 connected between a knuckle arm 3 at an angle of 1° and a body 4, and a solid suspension. The helical coil spring 6 is fixed to the upper spring seat 8 of the shock 7, the absorber 50, and the rod 7.
and the lower spring receiver 9 for fixing the shock absorber 5 midway.
The damping force of the shock absorber 5 is used together with the elastic force of the coil spring 6 to buffer the impact as a bounce stopper for ride comfort both during single-person driving and under maximum load, thereby improving handling stability. I'm trying.

However, in the case of the solid coil spring 6, if the space per unit winding between the upper and lower springs is lh, the possible deflection range is approximately ↓h of the free length 1h. +h has an unused space, and a rubber stopper 0 with a rod 7 inside is extended downwardly from the lower part of the upper spring seat 8 to regulate the shortest compression length of the coil spring 6 during impact, so that it can be used for high loads and Although the coil spring 6 has a predetermined absorption and buffering effect, the spring constant K (K = - Ji) is always constant, and the constant spring constant has to deal with the total load of the number of occupants, which changes accordingly. Therefore, for example, when four people are on board, four times the load is simply applied to the coil spring. 6, a larger load is applied to the coil spring 6 during compression due to the rebound of the coil spring 6 upon impact.
Coupled with this, the spring strength weakens as the number of passengers increases, making it impossible to expect the same ride comfort as when riding alone, and the ride comfort tends to vary depending on the number of passengers. There were drawbacks.

Further, since the solid coil spring 6 is made of @, it is easily corroded and has the disadvantage of poor durability.

<Purpose> The purpose of the invention of this application is to solve the technical problems of coil springs and springs for high load and slow wetting based on the above-mentioned prior art, and to cover the coil springs with an elastic material to prevent corrosion. To provide an excellent compression coil spring and a method for manufacturing the same, which are useful for the field of use of coil springs in the automobile industry, by preventing such occurrences and by varying the spring constant according to the number of occupants to always obtain stable ride comfort without variation. It is something.

In accordance with the above-mentioned object, the structure of the invention of this application whose gist is the above-mentioned claims is to solve the above-mentioned problems by using a helical compression coil spring main body formed in a predetermined manner so as to have a cross section in the expansion and contraction direction of the coil spring. The compression coil spring body is set in a spiral groove type cavity with a bulging capacity at the bottom, and an elastic material is injected into the cavity at high pressure to make the compression coil spring body float in the cavity, while the elastic material is applied around the entire circumference of the compression coil spring body. A coil spring that is surrounded and covered and integrally formed with the elastic material in at least one direction of expansion/contraction of the coil spring body so as to have a convex cross-section is installed together with a shock 7 boom of a vehicle wheel and interposed between each of the upper and lower spring seats. Therefore, at low loads, only the coil spring has a low spring constant, and at high loads, the upper and lower springs compress and contact each other through the convex elastic members, increasing the spring constant with a nonlinear configuration. The spring constant of the coil spring is varied according to the number of occupants to ensure spring action and buffering action, ensuring stable riding comfort and maneuverability at all times. Furthermore, technical measures have been taken to prevent corrosion of the coil spring and improve corrosion resistance and durability.

<Embodiment> Next, one embodiment of the invention of this application will be described below with reference to the drawings from FIG. 3 onwards.

In addition, the same reference numerals are given to the same parts as those in FIG. 1 for explanation.

6' is a hollow spiral compression coil spring which is the gist of the claimed invention and is lightweight. For example, a shock absorber 5 is interposed between an upper spring seat 8 and a lower spring seat 9 1c connected between a knuckle arm 3 and a body main body 4 of a front suspension 1 of an automobile, and damps the shock 7 absorber 5. The force characteristics are used in combination to absorb and buffer shock through the predetermined spring constant of the coil spring 6', thereby improving ride comfort and handling stability of the automobile.

Next, the manufacturing process of the coil spring 6' as an example will be explained in order.
A steel coil spring body C formed into a predetermined hollow spiral shape by the manufacturing method disclosed in VC No. 5-88395 is
As shown in the figure, a semicircular spiral cavity 13 having a recess 12 at the bottom is fitted into a spiral groove mold 14 formed on the outer periphery.

Then, a half-split outer mold 16.16 having a recess 12 at the lower part that fits the semicircular spiral cavity 3 of the spiral groove mold 14 and a semicircular spiral cavity 15 formed on the inner circumference is clamped in a predetermined manner. .

After mold clamping, each cavity 13 is injected by high-pressure injection until the molten thermoplastic elastomer (TPE) 18 as an elastic material is injected from the lower gate 17 of the outer mold 16 through the upper gate 19 of the outer mold 16. .14, the coil spring body 6'' is floating, and the lower part and below are the units between the upper and lower coil spring bodies 6'', 6'',...
If the space per winding is 1h, the elastomer 18 is surrounded by the coil spring body 6'' so as to have a free length of 1h and a wall thickness of h.

After injection molding, the hollow coil spring body C, which is released from the mold and whose entire circumference is covered with the thermoplastic nidistomer 18, has a cross-sectional convex portion 20 with a thickness of jh relative to the free length 1h at the lower part in the direction of expansion and contraction. are integrally formed, and the convex portion 20. In order to prevent the springs from shifting from each other during impact loading, and to ensure that the load is applied evenly to the convex portion 20,
As shown in Fig. 4, a metal member having a wall thickness of +h relative to the free length 1h, which has a roughened contact surface with an angular cross section;
Then, a spacer coil spring 21 made of resin is bonded in a predetermined manner, and a hollow compression coil spring 6' having a space of ah for the free length 1h is manufactured as shown in FIG.

As shown in FIG. 6, both ends of the steel coil spring body 6'' are fitted with plugs 22 and then covered with thermoplastic elastomer 18, thereby completely preventing corrosion from the ends. Also, a thermoplastic elastomer 1 of a predetermined thickness is applied to the entire circumference of the coil spring body 6'' except for the lower cross-sectional convex portion 20.
8, the corrosion resistance and durability of the entire coil spring body C are significantly improved.

Function> To explain the function of the compression coil spring 6' manufactured in this way in the above-mentioned front suspension 1 of the automobile, for example, when the load is low with one person riding, the shock spring 6' is applied to the shock absorber 50 fixed at the upper part of the rod 7. Upper spring seat 8 and lower spring seat 9 for fixing the shock absorber 5 midway
The coil springs 6' interposed between the upper and lower coil springs 6', 6', .
The damping force of the shock absorber 5 is calculated as shown in the spring diagram of FIG. When used in combination, a sufficient buffering effect can be achieved.

Furthermore, it is of course possible to design and use this non-linear spring characteristic as a spring constant for different purposes such as low load, high load, and dual use. Overall, a stable ride,
It is designed to improve maneuverability.

For example, when there are four people on board and a high load is applied, a high impact is applied to the coil spring 6', so that the upper and lower coil springs 61, 6', . . .
However, the metal or resin bonded to the upper and lower convex portions 20 of the thermoplastic elastomer 18 covering the coil spring body C attempts to produce a deflection greater than each spatial range of motion for the free length 1h. spacer coil spring 21
are mutually suppressed through contact.

Along with this, each of the protrusions 20 has the functions of a nonlinear spring body, a stopper body, and a buffer body, and together with the fact that the coil spring 6' is hollow, the eighth The spring constant of the spring diagram shown in the figure is varied to K Kamoni', and a unique nonlinear spring characteristic value is taken as a whole,
The strength and spring constant are '', and even the above-mentioned high impacts can be sufficiently buffered to provide a stable riding comfort.

Other Embodiments> It goes without saying that the embodiments of the invention of this application are not limited to the above-mentioned embodiments. For example, the embodiments of the invention of this application are not limited to the above-mentioned embodiments. It is also possible to cover a part of a thermoplastic elastomer with a convex cross section, or to apply it to a solid compression coil spring.Furthermore, the elastic material is not limited to thermoplastic elastomer resin, but can also be applied to any synthetic resin material. It may be made of a rubber material, etc., but the feature of the present invention is that it is composed of a resin elastic body that covers the entire periphery of the metal spring and has a convex portion on one side, which produces an effect. Furthermore, it goes without saying that the object of use is limited to front suspension joys, and also applies to rear suspensions.

Furthermore, the method for manufacturing compression coil springs is not limited to the high-pressure injection molding process using the spiral groove mold described above, but may also include dipping an elastic material with an appropriate viscosity, or coating it with a thick layer and then heating it to soften it. Various application methods are also possible, such as creating an uneven thickness structure using gravity.

However, the dimensions and shape are based on the above-mentioned limited spring spacing and dimensions.

Effects> According to the invention of the present application, in the compression coil spring which is interposed between the upper spring seat and the lower spring seat with a shock absorber for a vehicle wheel, and the manufacturing method, the entire circumference of the compression coil spring is is coated with an elastic material, the elastic material on at least one side of the compression coil spring in the expansion/contraction direction is integrally formed with a convex cross section, and another coil is attached to the elastic material, so that the compression/irradiation force is applied to the compression coil spring. The spring constant is varied in response to the impact, ensuring stable riding comfort that does not vary depending on the number of passengers, and has the excellent effect of significantly improving maneuverability.

In addition, by setting a helical compression coil spring body that has been preformed in a predetermined shape into a spiral groove shape having a bulging cavity in a part of the cross section in the direction of expansion and contraction of the coil spring, and injecting an elastic material into the cavity at high pressure, the coil spring body can be There is an effect that the elastic material floats in the cavity and is uniformly surrounded and coated around the entire circumference of the coil spring body.

By coating the entire circumference of the compression coil spring with an elastic material of a predetermined thickness, the coil spring is prevented from corrosion, the strength of the entire coil spring is improved, and the function as a compression body is fully fulfilled. This has the advantage of improving durability.

Furthermore, when the compression coil spring is made hollow, the overall weight is significantly reduced, which has the advantage of promoting weight reduction of the vehicle.

In addition, the compression coil bar has a small elastic convex part in the direction of expansion and contraction (the elastic convex part on one side serves as a stopper body for each upper and lower mutual spring, and also functions as a buffer body, making it a compressor with excellent impact resistance. It has the great advantage of being designed as a coil spring that can be used for both low load and high load applications.

[Brief explanation of drawings]

Fig. 1 is a front view of a conventional front suspension, Fig. 2 is a spring constant diagram of a conventional coil spring, Fig. 3 and the following show embodiments of the invention of this application, and Fig. 3 is a spiral groove type spring. FIG. 4 is an enlarged partial cross-sectional view of the spacer coil spring, FIG. 5 is an enlarged partial cross-sectional view of the hollow compression coil spring, and FIG. 6 is an enlarged cross-sectional view of the end of the coil spring.
7 is a diagram corresponding to FIG. 1, and FIG. 8 is a diagram corresponding to FIG. 2. 2...Wheel, 5...Shock 777-bar, 8...Upper spring receiver, 9...Lower spring receiver,
6'... Compression coil spring, 18... Elastic material, 2
0... Convex portion, 21... Other coil, 6
"...Coil spring body, 13.15...Cavity, 14...Spiral groove type Applicant Toyota Motor Corporation Figure 2 Figure 3 Figure 8 Figure 6 Figure 1 Figure 6 Procedure amendment (Spontaneous) December 13, 1988 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1. Indication of the case 1987 Patent in No. 197788 2. Title of the invention Compression coil spring and manufacturing method 3. Related Patent applicant representative Mori 1) Masatoshi 4・Agent ft0S ■ 6, Number of inventions increased by amendment None 7, Detailed explanation of the invention subject to amendment, page 8, lines 15 to 16 ``If the space per unit-turn is ih'' is corrected to ``If the proportion of space in the pitch of unit-turn per turn is ih, for example, if the free length of the space is 1h, then this'' will be corrected. Masu. ]

Claims (3)

[Claims] (1) In a compression coil spring that is attached to a shock absorber for a vehicle wheel and is interposed between an upper spring seat and a lower spring seat, the compression coil spring is covered all around with an elastic material, and the compression coil spring is covered with an elastic material. A compression coil spring characterized in that at least one of the elastic members in the expansion/contraction direction is formed to have a convex cross section. (2) In a compression coil spring that is attached to a vehicle wheel shock absorber and is installed between an upper spring seat and a lower spring seat, the compression coil spring is covered all around with an elastic material, and the compression coil spring is A compression coil spring, characterized in that another coil is attached to at least one of the elastic members in the expansion/contraction direction of the compression coil spring. (3) In a method for manufacturing a helical compression coil spring that is interposed between an upper spring seat and a lower spring seat and is also equipped with a shock absorber for a vehicle wheel, the method includes: □The main body of a helical compression coil spring that has been formed into a fixed shape is set in a spiral groove shape with a bulging cavity in a part of the cross section in the direction of expansion and contraction of the coil spring, and an elastic material is injected into the cavity to form one piece. A compression coil spring manufacturing method.