JPH10238507A - Negative pressure actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve negative pressure chamber airtighness by applying the constitution that a hard synthetic resin is used for forming a housing and a rod, as well as a soft thermoplastic plastic elastic material for forming a diaphragm and, then, the housing and the diaphragm as well as the diaphragm and the rod are jointed to each other at a thermal fusing process. SOLUTION: A housing 1 is formed as a hollow and approximately spherical body and made of such material as hard synthetic resin, polycarbonate, nylon 11 having upper and lower half-split bodies integrated with each other via a thermal fusion surface 9a. In addition, the housing 1 has a pipeline 12 at the upper part and a loose insertion hole 15 for passing a rod 6. Also, a diaphragm 2 is formed so that a thermoplastic elastic material softer than the hard synthetic resin of a hollow disc body and different therefrom in quality, such as hydroliquefied SBS block copolymer and olefin elastomer is bent in a projected state along the outer part, and integrated with the housing 1 via a thermal fusion surface 8a at the outer end. Also, the inner end is integrally formed via a thermal fusion surface 8b at both ends of the horizontal part of a T-shaped rod 6 made of a hard synthetic resin. According to this construction, the airtightness of a negative pressure chamber 3 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative pressure actuator which is used for an EGR valve, an exhaust brake, a switching valve for an intake and an exhaust passage, etc., has excellent airtightness and can be reduced in weight.

[0002]

2. Description of the Related Art As shown in FIG. 7, for example, a conventional negative pressure actuator comprises a housing 29 comprising an upper cover 35 and a lower cover 36;
A diaphragm 27 which divides the inside into a negative pressure chamber 33 having a conduit 32 and an atmosphere chamber 34 having an air hole (omitted in the drawing).
A spring 31 for urging the diaphragm 27;
The diaphragm 27 and the retainer 30 are integrally joined to each other, and are constituted by an interlocking rod 26. A method of using the negative pressure actuator 20 as an exhaust switching valve will be described. As shown in FIGS. 7 and 8, the exhaust switching valve is configured such that a butterfly type valve element 22 is rotated via a valve shaft 23 in a valve body 21. The other end of the valve shaft 23 protruding from the valve body 21 is fixed to a cam 25, and a lever 24 pivotally supported at the other end of the cam 25 and a rod 26 of the negative pressure actuator are connected. I have. FIG. 7 is under positive pressure, and the valve element 22 is open. Next, a negative pressure from a vacuum source (omitted in the figure) acts on a negative pressure chamber 33 of the actuator 20 via a pipe line 32, and the diaphragm 27 and the rod 26 Moves upward against the urging force of the spring 31 to bring the valve body 22 into the fully closed state. Further, when the negative pressure is released through the pipe line 32, the rod 26 moves downward by the urging force of the spring 31 as the pressure difference between the negative pressure chamber 33 and the atmospheric chamber 34 disappears, and the valve body 22 is fully opened. It is to return to.

In such a negative pressure actuator, the diaphragm is made of rubber and the other parts are made of metal, and the airtightness of the negative pressure chamber is ensured by clamping the diaphragm between the upper cover and the lower cover. Further, a through hole for connecting a rod to the diaphragm is provided for assembly.

However, in the method of caulking by sandwiching a diaphragm made of an elastic member such as rubber between the upper cover and the lower cover, airtightness may not be completely secured due to variations in caulking. In addition, for the connection between the diaphragm and the rod, it is necessary to take measures against airtightness such as applying a sealing material or using an O-ring. Further, a metal surface treatment agent such as a rust preventive treatment applied to the upper cover and the lower cover may affect the rubber material of the diaphragm and reduce durability.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a negative pressure actuator which is excellent in airtightness of a negative pressure chamber, does not use metal parts, and can be reduced in weight.

[0006]

Under such circumstances, the present inventors have conducted intensive studies and as a result, have used a hardened resin instead of metal for the housing and the rod, and integrated the hardened resin with the diaphragm by heat fusion. The present inventors have found that the above problems can be solved at once by using the soft thermoplastic elastic body formed, and have completed the present invention.

That is, a first invention of the present invention provides a housing, a pressure-sensitive movable member that divides the interior of the housing into a negative pressure chamber having a pipe and an atmosphere chamber having an air hole, and the pressure-sensitive movable member. In a negative pressure actuator comprising a biasing elastic body and a rod portion integrally linked to the pressure-sensitive movable member, the housing and the rod portion are made of a hard synthetic resin, and the pressure-sensitive movable member comprises the housing and the housing. An object of the present invention is to provide a negative pressure actuator which is formed integrally with a synthetic resin of the rod by thermal fusion, is softer than the synthetic resin, and is made of a thermoplastic elastic material of a different material. Further, the present invention is a negative pressure device having a return function, wherein an elastic body for urging the pressure-sensitive movable member extends downward from the pressure-sensitive movable member and is integrally formed with the housing by heat fusion. An actuator is provided.

According to a second aspect of the present invention, there is provided a pressure-sensitive movable member which divides a housing into a negative pressure chamber having a pipe and an atmosphere chamber having an air hole, and an integral part of the pressure-sensitive movable member. In an actuator comprising a rod portion interlocked with, the housing and the rod portion are
The pressure-sensitive movable member is made of a hard synthetic resin, and the pressure-sensitive movable member is formed integrally with the synthetic resin of the housing and the rod by heat fusion, and is made of a thermoplastic elastic material that is softer than the synthetic resin and of a different material. It is another object of the present invention to provide a negative pressure actuator in which a thin portion having a reversing function is formed on at least a part of the pressure-sensitive movable member.

According to a third aspect of the present invention, there is provided a housing having a conduit, a pressure-sensitive movable member located below the housing and integrally forming a negative pressure chamber with the housing; In a negative pressure actuator comprising a rod part integrally linked with a pressure-sensitive movable member, the housing and the rod part are made of a hard synthetic resin, and the pressure-sensitive movable member is softer than the synthetic resin and made of a different material. An object of the present invention is to provide a negative pressure actuator made of a thermoplastic elastic body.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The hard synthetic resin used for the negative pressure actuator according to the first to third inventions of the present invention is not particularly limited.
Nylon 11, nylon 12, ABS resin, polyamide resin, polyethylene resin, polyphenylene sulfide resin, polybutylene sulfide resin, polybutylene terephthalate resin, methacryl resin, and the like.

Further, the pressure-sensitive movable member (hereinafter, also referred to as a diaphragm) of the negative pressure actuator of the present invention is softer than the synthetic resin of the housing and the rod portion.
In addition, it is made of a thermoplastic elastic body of a different material, and such a thermoplastic elastic body is integrally molded with the synthetic resin by heat fusion. The heat fusion method may be in accordance with a known method, such as injection molding using a mold, ultrasonic welding, blow molding, calender molding, compression molding, transfer molding, and the like. Other methods may be used as long as they are conditions for fusing. In addition, the thickness of the pressure-sensitive movable member is not particularly limited and is appropriately selected depending on use conditions and materials, but may be about 0.2 to 2.0 mm.

The thermoplastic elastomer is not particularly restricted but includes hydrogenated SBS block copolymer, olefin elastomer, diene elastomer, urethane elastomer and plasticized polyvinyl chloride.

Further, the negative pressure actuator of the present invention can be used for an exhaust brake valve of an automobile or the like, an intake / exhaust passage switching valve, and the like.

[0014]

The negative pressure actuator of the present invention uses a hard synthetic resin for the housing and the rod, and a soft thermoplastic elastic body for the diaphragm, and heat-bonds the connection between the housing and the diaphragm and the connection between the diaphragm and the rod. Since they are integrally formed, the airtightness of the negative pressure chamber is improved. Further, since metal parts are substantially unnecessary, the weight can be reduced.
Further, the number of parts can be reduced, cost can be reduced, and assembling becomes easy.

[0015]

Next, the present invention will be described more specifically with reference to examples. Example 1 FIG. 1 is a sectional view of a negative pressure actuator according to a first embodiment of the present invention. In FIG. 1, a negative pressure actuator 10 includes a housing 1, a diaphragm 2 for dividing the inside of the housing into a negative pressure chamber 3 having a pipe 12 and an atmosphere chamber 4 having an air hole 5, a spring 7 for urging the diaphragm 2, and a rod. 6. The housing 1 is a hollow substantially spherical body and is divided into upper and lower divided bodies by a heat sealing surface 9.
The pipe 12 is formed in the upper part, and the rod insertion hole 15 is formed in the lower part. The diaphragm 2 is formed by bending a thermoplastic elastic body of a different material, which is softer than the synthetic resin of a hollow disk-shaped body, in a convex shape at the outer side, and is integrated with the housing 1 at the outer end via the heat-sealing surface 8a. Is molded. The inner end is integrally formed at both ends of a horizontal portion of a T-shaped rod 6 made of a hard synthetic resin via a heat-sealing surface 8b, and the spring is connected to the horizontal portion of the T-shaped rod 6. Installed on top. In the negative pressure actuator 10 having such a configuration, a negative pressure from a vacuum source (omitted in the drawing) acts on the negative pressure chamber 3 of the actuator 10 through the pipe 12 to communicate with the atmosphere in the atmosphere chamber 4. Due to the differential pressure, the diaphragm 2, the rod 6
Moves upward against the urging force of the spring 7 (FIG. 1).
Medium, two-dot chain line). Further, when the negative pressure is released via the pipe 12, as the pressure difference between the negative pressure chamber 3 and the atmosphere chamber 4 disappears, the rod 6 moves downward by the urging force of the spring 7 and returns to the original position. The heat-sealed surface 8a between the diaphragm 2 and the housing 1 is not limited to the above-described one.
As shown in FIG. 4, it is preferable that the upper surface of the protrusion 14 from the housing 1 and the lower surface of the end portion of the diaphragm 2 be integrally formed by a heat-sealed surface 8e because the bonding strength is further improved. According to the negative pressure actuator, the airtightness of the negative pressure chamber is further improved.

Embodiment 2 FIG. 2 is a sectional view of a negative pressure actuator according to another embodiment of the first invention of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
1 is different from FIG. 1 in that a disk-shaped diaphragm is used as the diaphragm 2 and a skirt-like member extending downward from the diaphragm 2 instead of the spring 7 and integrally formed with the housing and the heat-sealing surface 8b. Return function unit 13
a and that an I-shaped rod was used for the rod 6. Therefore, the rod 6 is integrally formed with the diaphragm 2 at the heat-sealing surface 8c. Further, the return function part 13a is in a contracted state at the time of positive pressure, and has an effect of returning to the original state when pulled. In the negative pressure actuator 10 having such a configuration, a negative pressure from a vacuum source (omitted in the drawing) acts on the negative pressure chamber 3 of the actuator 10 through the pipe 12 to communicate with the atmosphere in the atmosphere chamber 4. Due to the differential pressure, the diaphragm 2 and the rod 6 move upward against the restoring force of the return function part 13a (indicated by a two-dot chain line in FIG. 2). Further, when the negative pressure is released via the pipe 12, as the differential pressure between the negative pressure chamber 3 and the atmospheric chamber 4 disappears, the rod 6 of the return function of the return function part 13a moves downward and returns to the original position. The return function section 13a is not limited to the above-described one, and may be, for example, a hollow bellows-shaped one. According to the negative pressure actuator, the airtightness of the negative pressure chamber is further improved. Further, since no metal parts are used, the weight can be reduced.

Embodiment 3 FIG. 3 is a sectional view of a negative pressure actuator according to a second embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. That is, the difference from FIG. 1 is that the spring is omitted, the diaphragm is disc-shaped, and a ring-shaped thin portion having the same center is provided in the outer vicinity 11a and the intermediate position 11b.
That is, an I-shaped rod is used for the rod 6. Therefore,
The rod 6 is formed integrally with the diaphragm 2 at the heat fusion surface 8c. In the negative pressure actuator 10 having such a configuration, a negative pressure from a vacuum source (omitted in the drawing) acts on the negative pressure chamber 3 of the actuator 10 through the pipe 12 to communicate with the atmosphere in the atmosphere chamber 4. Due to the pressure difference, the diaphragm 2 and the rod 6 move upward against the reaction force of the thin portions 11a and 11b, and finally the thin portions 11a and 11b are reversed (two-dot chain line in FIG. 3). Further, when the negative pressure is released through the pipe 12, as the differential pressure between the negative pressure chamber 3 and the atmosphere chamber 4 disappears, the spring as in the first embodiment is used by the weight of the rod part 6 and the restoring force of the thin part. At least, the rod 6 moves downward and returns. It is preferable from the viewpoint of adhesive strength that the thin portion 11a is formed slightly away from the heat-fused surface 8a with the housing in the center direction. The thin portion is easily deformed by a slight negative pressure, and when a negative pressure is applied,
First, the concave rod 11 rises at the portion 11b. Then, when the negative pressure increases, the portion 11a is also dented, and the thin portion is finally inverted. The thickness of the thin portion may be appropriately selected depending on the conditions of use, the material of the diaphragm, and the like. In addition, the thin portion may be at least part of the pressure-sensitive movable member,
It is not limited to the two places in the above embodiment. According to the negative pressure actuator, the structure becomes simple, and the confidentiality of the negative pressure chamber is further improved. Also. The number of parts can be reduced,
Cost reduction can be achieved.

Embodiment 4 FIGS. 5 and 6 are sectional views of a negative pressure actuator according to a third embodiment of the present invention. In FIG. 5, a negative pressure actuator 10 includes a housing having a pipeline, and a diaphragm 2 which is located below the housing and is integrated with the housing to form a negative pressure chamber 3.
And a rod portion 6 integrally linked with the pressure-sensitive movable member 2
It is composed of The housing 1 is made of a hard synthetic resin having a hollow substantially hemispherical shape and an upper and lower two-piece body integrally formed on a heat-sealing surface 9b, and a pipe line 12 is heat-sealed to an upper portion and a diaphragm 2 to a lower portion. Is formed. The diaphragm 2 is softer than the synthetic resin of the hollow disk and is a thermoplastic elastic body of a different material, and is integrally formed with the flange 41 of the housing 1 on the upper surface of the outer end via the heat-fused surface 8f. The upper surface of the inner portion is formed integrally with the lower surface of both ends of the horizontal portion of the rod 6 forming a cup-shaped portion 61 through a heat-fused surface 8g. 6 on the horizontal part. Negative pressure actuator 1 having such a configuration
0, the negative pressure from the vacuum source (not shown)
2, the diaphragm 2 and the rod 6 move upward against the urging force of the spring 7 due to the pressure difference with the atmosphere acting on the negative pressure chamber 3 of the actuator 10 (FIG. 6). Further, if the negative pressure is released through the pipe 12 and the pressure is gradually increased, the rod 6 moves downward and returns to the original position by the urging force of the spring 7 as the differential pressure between the negative pressure chamber 3 and the atmosphere disappears. It is. According to the negative pressure actuator,
The confidentiality of the negative pressure chamber is further improved. In addition, since a large number of fused surfaces are secured, the strength is further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a negative pressure actuator according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a negative pressure actuator according to another embodiment of the first invention of the present invention.

FIG. 3 is a sectional view of a negative pressure actuator according to a second embodiment of the present invention.

FIG. 4 is a partially enlarged view showing another form of the heat-sealed surface portion between the housing and the diaphragm in FIG. 1;

FIG. 5 is a sectional view of a negative pressure actuator according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a state in which the diaphragm is moved upward by a negative pressure in FIG. 5;

FIG. 7 is a front view of a cross section of a part of a conventional negative pressure actuator for exhaust brake.

FIG. 8 is a left side view of FIG. 7 with a part cut away.

[Explanation of symbols]

1, 29 Housing 2 Pressure sensitive movable member 3, 33 Negative pressure chamber 4, 34 Atmospheric chamber 5 Atmospheric hole 6, 26 Rod 7, 31 Spring 8a, 8b, 8c, 8d, 8e, 8f, 8g 9a, 9b Heat-fused part (between hard resin and hard resin) 10, 20 Negative pressure actuator 11a, 11b Thin part 12, 32 Pipeline 13 Return function part 14 Projection part 27 Diaphragm 28 Stand 30 Retainer 35 Upper cover 36 Lower cover 41 Tsuba

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16J 3/02 F16J 3/02 A 10/00 10/00 A

Claims (5)

[Claims] 1. A housing, a pressure-sensitive movable member for dividing the inside of the housing into a negative pressure chamber having a pipe and an atmosphere chamber having an air hole, an elastic body for urging the pressure-sensitive movable member, and the pressure-sensitive member In a negative pressure actuator comprising a rod part integrally linked with a movable member, the housing and the rod part are made of a hard synthetic resin, and the pressure-sensitive movable member is thermally fused to the synthetic resin of the housing and the rod. A negative pressure actuator, which is formed integrally with the resin and is made of a thermoplastic elastic material which is softer than the synthetic resin and is made of a different material. 2. An elastic body for urging the pressure-sensitive movable member extends downward from the pressure-sensitive movable member and is integrally formed with the housing by heat fusion, and has a return function. Negative pressure actuator as described. 3. A negative pressure comprising a housing, a pressure-sensitive movable member that divides the inside of the housing into a negative pressure chamber having a pipe and an atmospheric chamber having an air hole, and a rod part integrally interlocked with the pressure-sensitive movable member. In the actuator, the housing and the rod portion are made of a hard synthetic resin, and the pressure-sensitive movable member is integrally formed with the synthetic resin of the housing and the rod by heat fusion, and is softer than the synthetic resin, and A negative pressure actuator comprising a thermoplastic elastic body of a different material, wherein a thin portion having a reversing function is formed on at least a part of the pressure-sensitive movable member. 4. A housing having a conduit, a pressure-sensitive movable member located below the housing and integrated with the housing to form a negative pressure chamber, and interlocked with the pressure-sensitive movable member. In a negative pressure actuator comprising a rod portion, the housing and the rod portion are made of a hard synthetic resin, and the pressure-sensitive movable member is made of a thermoplastic elastic body made of a softer and different material than the synthetic resin. Features a negative pressure actuator. 5. The hard synthetic resin is polycarbonate, nylon 11, nylon 12, ABS resin, polyamide resin, polyethylene resin, polyphenylene sulfide resin, polybutylene sulfide resin, polybutylene terephthalate resin, or methacrylic resin. 5. The negative pressure actuator according to claim 1, wherein the plastic elastic body is a hydrogenated SBS block copolymer, an olefin elastomer, a diene elastomer, a urethane elastomer, or plasticized polyvinyl chloride.