JPS6021243B2 - actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an actuator formed by blow molding a parison.

BACKGROUND OF THE INVENTION In general, actuators for adjusting the air intake damper and other mechanisms of automobiles are used to adjust air intake dampers and other mechanisms.

This actuator is formed in the snake ridge by blow molding a parison of synthetic resin. and,
Conventionally, in this type of actuator, the valleys and crests of the snake valley portion are formed to be uniform in size, but such an actuator has the following drawbacks.

That is, as shown in Figures 1 to 6, when a synthetic resin parison, which had a circular cross section during extrusion, is inserted into two-part molds 2 and 3 for blow molding and the molds are clamped. The crimped flanges la and lb at both the upper and lower ends are crushed and flattened at the same time as the cutting, resulting in a bartending line 4 that bisects the flanges la and lb into front and rear halves.
As can be seen from FIGS. 1 and 3, the section 5 is located far away from the center, but it is perpendicular to the bartending line 4 and bisects the flanges la and lb to the left and right. 2 and 3, the portion 6 will be located closer to the center.

Therefore, when air is next blown into the interior through the blowing pin 7, the balisong 1 starts to expand and expands along the inner wall of the bellows groove 8 of the molds 2 and 3. Since the distance L2 from the portion 6 to the trough 10 of the bellows groove 8 is larger than the distance L to the trough, when the parison reaches the trough 9 as shown in the fifth figure, The portion 11 is relatively unstretched and thickens;
The parison 1 has the valley portion 10 as shown in FIG.
When that point is reached, the portion 12 is sufficiently stretched and becomes extremely thin.

If the portion 12 is extremely thin like this, when the actuator is expanded and contracted by repeated vacuum operations in a high-temperature atmosphere, it will be difficult for the thin portion 12 to maintain its shape, and there is a risk that the certain shape will collapse. be.

In addition, in order to prevent this certain shape from collapsing, the portion 12
In order to increase the thickness of the supply parison 1, it is necessary to make the supply parison 1 thick. However, if the parison 1 is made thick, the portion 11 becomes too thick, resulting in poor operability. In this way, in the bellows-type actuator, the wall thickness is uneven due to the difference in the blow ratio in the circumferential direction of the bellows parts near the flanges la and lb, which are crimped during blow molding. However, if the design focuses on maintaining the shape, good operability cannot be obtained.

The present invention was made in view of the drawbacks of the prior art, and aims to provide an actuator with good operability and heat resistance by making the wall thickness of the bellows portion uniform at both ends. .

For this reason, in the present invention, the present invention comprises head plates at both ends, a flat flange which is narrow in width relative to its length and protrudes outward from the center of the head plate, and a bellows portion having a substantially constant outer diameter located between the head plates. In the actuator, the depth of the trough of the belly of the lake in a cross section parallel to the surface of the flat flange and along a barten line that bisects the flange into front and back and further bisects the belly of the snake into front and back. Let d be the depth of the valley of the German enemy's position in a cross section along a plane that is perpendicular to the bartending line, bisects the flange left and right, and further bisects the snake's abdomen left and right. When is d2, the depth of the valley part of the bellows part is d, 11 at the longitudinal center of the bellows part, and d,>m at both ends of the bellows part. The problems of the prior art have been solved by gradually changing the structure.

Next, one embodiment of the present invention will be described with reference to FIGS. 7 to 10.

21 indicates an actuator, and this actuator 21
is integrally formed by blow-molding the parison 22 inside a two-part mold, and end plates 24 and 25 are formed at both ends of the bellows part 23, and a length Fan flat flanges 26 and 27 having a narrower width than the other are formed in a protruding manner.

The bellows portion 23 is formed to have a substantially constant outer diameter. That is, the outer diameters of the respective peaks are all formed to be substantially constant. As shown in FIG. 7, the diameter of the trough of the bellows part 23 in the cross section along the bartending line PL that bisects the bellows part 23 into two halves in the longitudinal direction is maximum at the central part in the length direction and at both ends. It gradually decreases as you go.

In other words, the depth d of the valley gradually increases from the center to both ends in the length direction. Further, as shown in FIG. 8, the diameter of the trough of the bellows part 23 in a cross section taken along a plane that is perpendicular to the bartending line PL and bisects the bellows part 23 into left and right halves is equal to the diameter of the trough in the longitudinal direction. It is minimum at , and gradually increases toward both ends.

That is, the depth of the valley becomes gradually shallower from the center in the length direction to both ends. As shown in FIG. 10, the valley has a circular or oval shape, and the portions not included in the cross section along the bartending line PL and the cross section along the plane perpendicular to the bartending line PL are curved. are connected smoothly by.

Then, in the longitudinal center of the bellows part 23, d
, 〒 is the original, while at both ends the depth of the valley is gradually changed so that d, > d2.

The actuator 21 is integrally blow-molded inside a two-part mold as in the prior art, and at that time, the flanges 26 and 27 at both ends are clamped and crimped by the mold of the parison 22, and are notched. formed by

These series of molding steps are the same as those shown in FIGS. 1 to 6 above. In the blow molding of this actuator 21, when the parison 22 is inserted into the split mold, it has a hollow cylindrical shape, but since it is crimped at the flanges 26 and 27 by the mold clamping, the bartending line PL In FIG. 7, which is the cross section taken along the line PL, the portion 28 of the parison 22 is far away from the center, and in FIG. 29 will be located closer to the center.

As a result, as is clear from FIGS. 7 and 8, the distances a, and a2 from the portions 28 and 29 to the top of the crest of the bellows portion 23 are much smaller for a, than b2. . However, since this actuator 21 has the above-described shape, in FIG. 7, the portion 28, which tends to be thick due to the small blow ratio, is expanded by blowing air into the inside. , is extended until it reaches the recess 3, which is deeper than the central part in the length direction, and at this time, the recess 3
Since the zero depth is deep, it comes into contact with the cooled bellows part 23 of the mold at an early stage, and as a result of fixing the stretching point, thinning is promoted and the thickness is moderately thin.

In addition, in Fig. 8, the part that tends to be thin normally expands due to air being blown into the interior and reaches the recess 31, but this recess 31 is shallower than the recess in the center. , the stretching ratio in the recess 31 is not too small or too thin. In this way, the wall thickness of the bellows portion 23 becomes substantially uniform throughout.

Next, FIGS. 11 and 12 show other embodiments.

As shown in FIG. 11, the depth d of the valley in the cross section along the bartending line PL is gradually deepened from the center in the length direction to both ends, and as shown in FIG. The depth of the valley in the cross section perpendicular to the line PL is constant. Further, FIGS. 13 and 14 show still other embodiments.

As shown in FIG. 13, the depth d,' of the valley in the cross section along the bartending line PL' is constant, and as shown in FIG. The depth becomes gradually shallower from the center in the length direction to both ends. In both the cases of Figures 11 and 12 and Figures 13 and 14, d, ≠ in the center, and gradually d, > towards both ends. .

This configuration makes it possible to obtain an actuator that is much more practical than those of the prior art, even if it is somewhat smaller than those of FIGS. 7 to 10.

According to the present invention, the depth d of the valley of the bellows portion in a cross section along the barten line that bisects the bellows portion into front and rear halves,
The relationship between the depths of the valleys in the cross section along the plane perpendicular to the bartending line and bisecting the bellows part into left and right halves is d at the center in the longitudinal direction, and d at the main part, while at both ends. Since we made it so that d, > d2, the depth of each part near the bird flat flange at both ends is always d, > d2.
Due to mold clamping during molding, the parison part in the cross section along the bartending line, which tends to be thick, is stretched more rapidly, while the parison part, in the cross section along the plane perpendicular to the bartending line, which tends to be thin, is stretched more rapidly. Although the ratio is high, stretching occurs gradually;
It is not so thin, therefore, it is possible to have a well-balanced and uniform wall thickness at both ends, and since the parison maintains a nearly perfect circle in the center, the depth of each part is There is no change in thickness.

In this way, the actuator was unavoidable in the conventional method of blow-molding a bellows abdomen with a constant outer diameter inside a two-part mold to form flat flanges with a narrow width relative to the length on the head plates at both ends. It is possible to eliminate the unevenness in wall thickness at both ends of the bellows part, prevent collapse in a high-temperature atmosphere, and eliminate the need to increase the thickness unnecessarily to prevent collapse, thereby improving operability.

[Brief explanation of the drawing]

Figures 1 to 6 show examples of substructures. Figure 1 is a cross-sectional view of the parison with the parison cut away, Figure 2 is a cross-sectional view along the Rollo line of Figure 1, and Figure 3 is a cross-sectional view of the parison. Figure 4 is a cross-sectional view taken along line N-W in Figure 1, Figure 5 is a cross-sectional view when blow molding is completed, and Figure 6 is a cross-sectional view taken along line W- in Figure 5. Figures 7 to 10 show one embodiment of the present invention.
The figure is a sectional view taken along the bartending line of the actuator, FIG. 8 is a sectional view taken along a plane perpendicular to the bartending line of the actuator, and FIG. 9 is a bottom view taken from section KK in Fig. 7. Figure 10 is a cross-sectional view taken along the line X-X in Figure 8.
1 and 12 are a front view and a side view showing another embodiment of the invention, and FIGS. 13 and 14 are a front view and a side view showing still another embodiment of the invention. 21... Actuator, 23... Bellows part, 24, 25... End plate, 26, 27...
・Flat flange, PL...Barten line, d,
, d2... Depth of the valley. False figure 2 figure omitted 3 figure fin 4 figure omitted 5 figure fin 6 figure 2 figure *8 box ○ figure'○ figure fin

Claims (1)

[Scope of Claims] 1 Consisting of head plates at both ends, a flat flange that is narrow in width relative to its length and protrudes from the center of the head plate, and a bellows portion having a substantially constant outer diameter located between the head plates. , the depth of the valley of the bellows part in a cross section parallel to the plane of the flat flange and along a parting line that bisects the flange into front and back halves and further bisects the bellows part into front and back halves is d_1. , when the depth of the valley of the bellows part in a cross section along a plane that is perpendicular to the parting line, bisects the flange left and right, and further bisects the bellows part left and right, is d_2;
The depth of the valley of the bellows part is gradually changed such that d_1≈d_2 at the longitudinal center of the bellows part, and d_1>d_2 at both ends of the bellows part. actuator. 2. The depth d_1 of the valley of the bellows part is gradually deepened from the center in the longitudinal direction of the bellows part to both ends, and the depth d_2 of the valley part of the bellows part is set to the length of the bellows part. 2. The actuator according to claim 1, wherein the actuator is made gradually shallower from the central portion in the widthwise direction toward both ends. 3. The depth d_1 of the valley of the bellows part is gradually deepened from the center in the longitudinal direction of the bellows part to both ends, and the depth d_2 of the valley part of the bellows part is set to the length of the bellows part. 2. The actuator according to claim 1, wherein the actuator is constant in the longitudinal direction. 4 While keeping the depth d_1 of the valley of the bellows portion constant,
2. The actuator according to claim 1, wherein the depth d_2 of the trough of the bellows portion is made gradually shallower from the center in the longitudinal direction of the bellows portion toward both ends.