JPH0345894Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an air pressure booster for reducing the force applied to the brake pedal by using the negative pressure of the intake manifold of the engine in an automobile.

[Prior art]

2. Description of the Related Art Conventionally, an air pressure booster is known that utilizes negative pressure in an intake manifold of an automobile engine to double the depression force on a brake pedal and transmit the same to a master cylinder. This air pressure booster divides the inside of the shell body into two chambers, a front chamber and a rear chamber, by a power piston that is displaceably provided in a shell body consisting of a front shell and a rear shell via a diaphragm. Negative pressure is introduced from the engine intake manifold into the front chamber, atmospheric air is introduced into the rear chamber, and thrust is generated in the power piston by the differential pressure between the front chamber and the rear chamber,
The thrust is transmitted to an output shaft provided on the power piston, and a master cylinder is actuated via this output shaft.As an example, as shown in FIG.
An opening 3 for receiving a part of the master cylinder 2 is formed, and a flange 5 of the master cylinder 2 is attached to the front shell surface having this opening 3 via a seal member (seal ring) 4, and two outer circumferences are connected to bolts 6. There is also one that is attached by fastening with a nut 7, thereby maintaining the airtightness of the front chamber.

However, in such a pressure booster, in view of the recent trend toward weight reduction of vehicles, efforts have been made to make the shell thinner, and the flange 5 of the master cylinder 2 is placed on the flat and thin front shell surface as described above. Since it is attached only by tightening bolts and nuts at two locations on the outer periphery, when negative pressure is introduced into the front chamber, it is sucked by this negative pressure and is tightened by the bolts 6 and nuts 7 on the periphery of the opening 3 of the front shell 1. Due to the differential pressure between the negative pressure in the front chamber and the outside air pressure, the part between the two fastening parts curves toward the front chamber as shown by the two-dot chain line in FIG. 3, and the flange 5 of the master cylinder 2 and the front shell 1 A gap 8 was created between the sealing member 4 and the front shell 1, and there was a possibility that the airtightness of the front chamber could not be maintained.

[Problem that the invention attempts to solve]

The problem to be solved by the present invention is to ensure that even if the front shell is thinned, the airtightness of the front chamber can be reliably maintained when negative pressure is introduced into the front chamber.

[Means for solving problems]

In the present invention, a front shell and a rear shell are connected to each other, and a shell main body is divided into a front chamber and a rear chamber by a power piston, an opening is provided on the master cylinder receiving side of the front shell, and the opening is In the air pressure booster, in which a sealing member is provided between a front shell surface and a flange surface of a master cylinder to maintain airtightness of the front chamber, an inner circumference is provided at the periphery of the opening of the front shell. A tapered edge is formed that gradually protrudes toward the flange surface from the side toward the outer circumferential side, and the tapered edge is elastically deformed into a flat shape by attaching the master cylinder to the front shell, so that the tapered edge is elastically deformed into a flat shape so as to meet the flange surface. It is characterized in that it is in close contact and that an elastic force directed toward the flange surface is always applied to the outer circumferential side.

[Effect]

When negative pressure is introduced into the front chamber, the differential pressure between the front chamber and the outside of the front shell causes it to be sucked into the front shell or toward the front chamber. Since elastic force (initial strain) is applied in the plane direction, there is no gap between the sealing member and the front shell, and the airtightness of the front chamber is ensured when negative pressure is introduced into the front chamber. is maintained.

[Effect of idea]

Even if the front shell is made thinner, the airtightness of the front chamber can be reliably maintained when negative pressure is introduced into the front chamber by only slightly changing the molded shape of the front shell.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Note that FIG. 1 is a cross-sectional view of FIG. 3 rotated approximately 90 degrees.
The air pressure booster of this embodiment has the same basic structure as the conventional air pressure booster, and in particular, the bolt 6 shown in FIG. The vicinity of the part where the bolt 24 in FIG. A tapered edge 14 is formed that protrudes toward the flange surface. That is, the shell main body 1 consists of a front shell 11 and a rear shell 15.
A power piston (not shown) displaceably disposed within the shell body 16 via a diaphragm (not shown) divides the inside of the shell body 16 into two chambers, a front chamber 17 and a rear chamber (not shown). , front room 17
Negative pressure is introduced from the engine intake manifold through the pipe connection 18, and when the brake pedal (not shown) is operated, an input shaft 19 and a valve mechanism (not shown) are connected to the brake pedal.
Atmosphere is introduced into the rear chamber through the front chamber 17.
A thrust is generated in the power piston due to the pressure difference between the front chamber and the rear chamber, and the thrust is transmitted to the output shaft 20 provided on the power piston, and via this output shaft 20, the master cylinder 12 attached to the front shell 11 is activated. An opening 13 for receiving the master cylinder 12 is formed in the center of the front shell 11, and a cylinder is formed at the periphery of the opening 13 from the inner circumferential side to the outer circumferential side of the opening 13. A tapered edge 14 protruding in the direction of the flange surface of the master cylinder 12 is formed, and two outer circumferences of the flange 22 of the master cylinder 12 are connected to the front shell surface 21 having the opening 13 between the front shell surface 21 and the flange 22. They are fastened with bolts 24 and nuts 25 with a seal member (seal ring) 23 interposed therebetween. In this way, the tapered edge 14 formed at the periphery of the opening 13 is flattened by the tightening force of the bolt 24 and nut 25, as shown in FIG. 1 (two-dot chain line) and FIG. The tapered edge 14 is elastically deformed and brought into close contact with the flange surface of the master cylinder 12, and an elastic force directed toward the flange surface is always applied to the outer peripheral side of the tapered edge 14. Thereby, even if negative pressure is introduced into the front chamber 17, the sealing performance of the sealing member 23 is not lost, and the airtightness of the front chamber 17 is maintained.

The air pressure booster configured as described above performs a boosting action to reduce the depression force on the brake pedal, similar to the conventional air pressure booster. At that time, front room 17
When negative pressure is introduced into the front shell 1, the pressure difference between the inside of the front chamber 17 and the outside of the front shell 11 causes the front shell 1 to
1 is sucked toward the front chamber 17, but at this time, an elastic force directed toward the flange surface of the master cylinder 12 is always applied to the outer circumferential side of the tapered edge 14 at the periphery of the opening 13 of the front shell 11. Therefore, the seal member 23 and the front shell 11
There will be no gap between the two. Therefore, the airtightness of the front chamber 17 can be maintained reliably by only slightly changing the molded shape of the front shell 11.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the present invention, with Figure 1 being a vertical sectional side view of the main parts, Figure 2 being a partially cutaway side view, and Figure 3 being a conventional air pressure booster. It is a vertical side view of the principal part showing an example. 11... Front shell, 12... Master cylinder, 13... Opening, 14... Annular tapered edge,
15...Rear Ciel, 16...Ciel main body, 17
...Front chamber, 21...Front shell surface, 2
2...Flange, 23...Seal member (seal ring).

Claims (1)

[Scope of Claim for Utility Model Registration] A power piston defines a front chamber and a rear chamber within a shell body formed by connecting a front shell and a rear shell, and an opening is provided on the master cylinder receiving side of the front shell, In the air pressure booster in which a sealing member is provided between the front shell surface having the opening and the flange surface of the master cylinder to maintain airtightness of the front chamber, the periphery of the opening of the front shell is provided with a sealing member. is formed with a tapered edge that gradually protrudes toward the flange surface from the inner circumferential side toward the outer circumferential side, and the tapered edge is elastically deformed into a flat shape by attaching the master cylinder to the front shell. An air pressure booster characterized in that it is in close contact with the flange surface and that an elastic force directed toward the flange surface is always applied to the outer circumferential side.