JPH044929Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a hydraulic fluid reservoir for a master cylinder used in a vehicle, and more specifically, to a diaphragm mounting structure in a sealed reservoir.

(Prior Art) A. General Sealed Reservoir A sealed type reservoir has been known as one type of hydraulic fluid reservoir. This sealed reservoir has a diaphragm placed between the opening of the reservoir body and a cap that is fitted to cover the opening to prevent the hydraulic fluid from absorbing water, to prevent pressure generation inside the reservoir, and to prevent the fluid from being absorbed. This is to prevent leakage.

Here, the sealing diaphragm is made of a flexible material such as rubber, and its outer periphery is placed between the reservoir body and the cap. In this case, the lower surface of the bead portion on the outer periphery of the diaphragm rests on the upper end surface of the reservoir body, and the upper surface receives the tightening force from the cap side.

B. General Problems with Sealed Reservoirs In the sealed reservoirs described above, the diaphragm is made of a flexible material, which presents considerable difficulties in keeping it in the proper configuration. For example, when attaching the cap to the reservoir body, it is unavoidable that the diaphragm will twist due to the screwing force of the cap, or that the outer bead of the diaphragm will protrude inward due to the tightening force. .

C. First conventional example for solving protrusion, etc. By the way, as a means to prevent such twisting and protrusion, a bead on the outer periphery of the diaphragm,
A technique of arranging a low friction sliding ring or retainer plate made of plastic or the like is known (for example, see Japanese Utility Model Application Publication No. 14765/1983). However, from the viewpoint of cost reduction or work efficiency in attaching and detaching the cap, other preventive measures that do not require separate parts such as a sliding ring or retainer plate are desired.

D Second conventional example for solving protrusion etc. As a method that does not require separate parts,
As shown in the publication No. 19740, a thin lip-shaped portion is provided on the outer edge of the diaphragm serving as a partition, and the lip-shaped portion is hooked onto the upper outer peripheral wall of the reservoir body (tank). It is possible that

However, simply providing a thin hanging piece on a part of the outer peripheral bead of the diaphragm and sandwiching the outer peripheral bead including the hook between the upper end of the reservoir body and the cap does not work as described above. Furthermore, when the cap is installed, the hook is deformed, and the outer peripheral bead of the diaphragm easily protrudes into the tank. This problem is more likely to occur when replenishing the hydraulic fluid later. It is thought that such a problem becomes noticeable because the hydraulic fluid that adheres to the outer peripheral bead and becomes sticky due to softening increases the slip resistance between the reservoir body side and the outer peripheral bead.

(Problem to be solved by the invention) This invention was made in consideration of each of the above points, and does not require separate parts and can reliably prevent protrusion of the diaphragm, etc. It is.

(Summary of the invention) In this invention, the protrusion of the diaphragm, etc. is reliably prevented by a combination of the following three means (a), (b), and (c).

(a) By making the entire thick outer peripheral bead portion of the diaphragm function as a hooking piece, a sufficient function as a hooking piece is obtained.

(b) By providing a specific tapered portion (tapered surface) that fits each other over the entire circumference on both the outer peripheral bead of the diaphragm and the upper outer peripheral wall of the reservoir body, the outer peripheral bead of the diaphragm can be easily adjusted when the cap is attached. The diaphragm is shaped to be pushed outward in the radial direction of the reservoir body, effectively preventing the diaphragm from twisting or protruding inward.

C. The thin part following the thick outer bead part is sandwiched and supported between the upper end surface of the reservoir body and the cap, and the outer bead part is reliably prevented from protruding inward as a hooking piece. That's what I do.

(First Embodiment) The first embodiment is an example of application to a cap having a screw-in type. FIG. 1 is a side sectional view showing the overall structure of a hydraulic fluid reservoir according to a first embodiment.

An internal space 1 for storing hydraulic fluid is a reservoir body 2.
It's inside. The reservoir body 2 is a cylindrical container made of plastic with an opening 3 at the top, and its inner diameter is substantially uniform from the opening 3 at the top to the bottom. The bottom side of the reservoir body 2 is attached and fixed to a master cylinder (not shown) of an automobile brake system. On the bottom side, there is a float setting part 4 on the inside, a reed switch setting part 5 on the outside, and supply ports 6a on both sides of the bottom.
6b are provided respectively. These two supply ports 6a and 6b form a passage for supplying the hydraulic fluid in the reservoir to the master cylinder.
When installing the reservoir, these two supply port portions are fitted into the boss portion on the master cylinder side. In the figure, the reservoir body 2 is inclined as a whole, but this slope corresponds to the slope of the attachment part of the master cylinder and is intended to keep the reservoir horizontal in the final installation stage.

The upper part of the reservoir main body 2 near the opening 3 is thicker than other parts, and a thread 7 is cut in the outer peripheral part. This male screw 7 is for attaching the cap, and here this male screw 7 is used for attaching the cap.
A tapered surface 8 is provided at the top of the portion apart from the screw 7. The tapered surface 8 is located from the upper end of the reservoir body 2 to the starting end of the male thread 7. The outer diameter of the tapered surface 8 increases in the same way all around the circumferential direction of the reservoir body 2 as it goes downward. Therefore, the area of the upper end surface of the reservoir body 2 is considerably smaller than the cross-sectional area of the male thread 7.

The cap 9 attached to the reservoir body 2 is also made of plastic, and the open lower cylindrical portion 10 has a larger diameter than the closed upper cylindrical portion 11. That is, a female thread 12 that fits the male thread 7 of the reservoir body 2 is cut on the inner circumferential side of the outer circumferential cylinder part. in this case,
The lower end of the female thread 12 reaches the opening end of the cap 9, but the upper end ends midway through the outer cylindrical portion 10. From the upper end of this female thread 12, the cap 9
The portion reaching the step surface 13 forms an inner wall surface 14 having approximately the same diameter as the thread diameter of the male screw 7 provided on the reservoir body 2 side. The inner wall surface 14 faces the tapered surface 8, so that they together form a ring-shaped recess 15. This ring-shaped recess 15 is a place for receiving an outer peripheral portion 17 of a sealing diaphragm 16.

The diaphragm 16 is made of rubber and consists of a thin portion 18 that can be easily elastically deformed in response to a pressure difference, and a thick outer peripheral portion 17. Diaphragm 1
6 is provided with a thin walled portion 18 that crosses the opening 3, and an outer peripheral portion 17 that connects the reservoir body 2 and the cap 9.
Supported between. The outer peripheral portion 17 of the diaphragm 16 also serves as a sealing member, so that the inner space 1 of the reservoir body 2 is tightly cut off from the cap side space 19 and the outside air by the diaphragm 16. The cap side space 19 communicates with the outside air through a passage 20 provided on the inner surface of the cap 9 and a thread clearance.

Now, the outer peripheral part 17 of the diaphragm 16 is different from the recessed part 15 except that its height is slightly lower.
The shape is suitable for That is, the upper surface 17a of the outer circumferential portion 17 is in contact with the step surface 13 of the cap 9, and both side surfaces 17b and 17c of the inner and outer circumferences of the outer circumferential portion 17 are in contact with the inner wall surface 14 of the cap 9 and the tapered surface 8 of the reservoir body 2, respectively. There is. Therefore,
When installing the cap 9 by screwing it into the reservoir body 2, the upper surface 1 of the outer periphery 17 of the diaphragm 16
The tightening force of the cap 9 is transmitted to the cap 7a through the stepped surface 13 on the cap 9 side. This tightening force forces the outer circumferential portion 17 of the diaphragm 16 downward, and correspondingly, a frictional force related to the tightening force is generated on the tapered surface 8 as well. This frictional force becomes sliding resistance. However, since the tapered surface 8 has a uniform shape over the entire circumferential direction of the reservoir body 2, the frictional force is relatively small, and the outer peripheral portion 17 is guided along the tapered surface 8 and slightly It deforms elastically to ensure the seal of the area. Particularly in this case, the upper outer circumferential wall of the reservoir body 2 is located inside the outer circumference 17 of the diaphragm 16, and the thin portion 18 continuing to the outer circumference 17
a is the stepped surface 13 of the cap 9 and the reservoir body 2
Since it is pressed more strongly between the upper end surface of the outer circumferential portion 17 and the outer peripheral portion 17, it is possible to effectively prevent the thick outer circumferential portion 17 from protruding inward. Furthermore, while such squeezing is being performed, the tapered surface 8 whose outer diameter becomes uniform as it goes downward acts to push the outer peripheral part 17 outward in the radial direction. There is no way that it will protrude inward.

(Second Embodiment) The second embodiment is an example of application to a cap having a push-in type. FIG. 2 is a sectional view of a main part showing the upper structure of a hydraulic fluid reservoir according to a second embodiment.

In this second embodiment, since the cap is a push-in type, there is no threaded part as in the first embodiment, but the overall structure of the cap, reservoir body, and diaphragm is the same as in the first embodiment. It is similar to Therefore, similar components are given the same reference numerals to simplify the explanation.

Here again, the sealing diaphragm 16 has a thinner part 1, although the overall shape is slightly different.
8 and a thick outer peripheral portion 17. and,
The thick outer peripheral portion 17 is connected to the stepped surface 1 of the cap 9.
3, an outer surface 17b that contacts the inner wall surface 14 of the large diameter outer cylindrical portion 10 of the cap 9, and an inner surface 17c that contacts the upper tapered surface 8 of the reservoir body 2. The outer diameter of the tapered surface 8 on the upper outer periphery of the reservoir body 2 increases as it goes downward. Therefore, a locking portion 21 is provided at the lower part of the tapered surface 8 and is perpendicular to the wall surface of the reservoir body 2. This locking part 21 has
A protruding piece 22 provided at the lower part of the outer peripheral portion 17 of the diaphragm 16 is locked. It is preferable that the protruding piece 22 extends around the entire circumference in order to ensure secure locking. The attachment of the diaphragm 16 to the reservoir body 2 is quite strong even if the protruding piece 22 is only locked to the locking part 21. However, the cap 9 further increases its attachment strength and protects the diaphragm 16. Outer cylindrical portion 10 of cap 9
A supporting piece 23 facing inward is provided at the lower part of the holder. The support piece 23 supports the lower surface of the protrusion piece 22 and reinforces the locking force of the protrusion piece 22. Therefore, it is preferable that the support piece 23 also has a structure extending all around the circumference like the projecting piece 22, but in order to communicate the cap side space 19 with the outside air, a notch 24 is provided in the part that continues to the passage 20.
It is necessary to provide

Here, as methods for attaching and fixing the diaphragm 16 and the cap 9 to the reservoir body 2, there are two methods: attaching the diaphragm 16 to the reservoir body 2 and then attaching and fixing the cap 9 separately from the diaphragm 16; A conceivable method is to attach the reservoir body 2 to the reservoir body 2 and then attach and fix both to the reservoir body 2. The former method has the disadvantage that the supporting piece 23 cannot be made so large in order to facilitate the pushing of the cap 9, but the latter method does not have such a disadvantage and is relatively easy to assemble. can.
However, whichever method is adopted, the effect of preventing the diaphragm 16 from twisting or protruding is almost the same as in the first embodiment. Of course, since the cap is a push-in type, in this second embodiment,
Diaphragm twisting is rarely a problem.

(Effects of the invention) In this invention, (a) the entire thick outer peripheral bead portion 17 of the diaphragm 16 is hooked on the upper outer peripheral wall of the reservoir body 2, thereby effectively protruding the outer peripheral bead portion 17; (b) The inner surface 17c of the outer peripheral bead portion 17 and the specific tapered surface 8 provided on the upper outer periphery of the reservoir body 2 are brought into contact with each other to prevent twisting of the diaphragm 16 when the cap 9 is attached. (c) By sandwiching and supporting the thin portion 18a following the thick outer bead portion 17 between the upper end surface of the reservoir body 2 and the cap 9, This is to prevent protrusion. With these three means, according to this invention, the problem of twisting and protrusion of the diaphragm 17 can be effectively and reliably solved without using separate parts such as a ring member.

In particular, in this invention, the thick outer peripheral bead portion 17 of the diaphragm 16 is pushed out radially outward of the reservoir body 2 by a specific tapered surface, and in addition, the outer peripheral bead portion 17 Since the thin portion 18a following the portion 17 is supported by the narrow upper end surface of the reservoir body 2, the diaphragm 16 can be supported and sealed reliably. Therefore, the diaphragm 16 can always be maintained in an appropriate configuration not only when a new hydraulic fluid reservoir is filled with hydraulic fluid, but also when the hydraulic fluid is replenished later.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the overall configuration of a first embodiment of this invention, and FIG. 2 is a sectional view of essential parts showing a second embodiment of this invention. 1...Internal space, 2...Reservoir body, 3...
Opening, 8...Tapered surface, 9...Cap, 10...
... Lower cylinder part (outer cylinder part), 14 ... Inner wall surface, 1
6...Diaphragm, 17...Outer periphery, 20...
aisle.

Claims (1)

[Scope of utility model registration request] A reservoir body having an internal space for storing hydraulic fluid, a cap attached to the reservoir body so as to close an opening provided at the upper part of the reservoir body, and a cap provided across the opening between the reservoir body and the cap. A hydraulic fluid reservoir comprising a diaphragm whose outer periphery is supported between the diaphragms and a passage communicating the cap-side space of the diaphragm with outside air, the outer cylindrical portion of the cap being connected to the upper outer periphery of the reservoir body. In the hydraulic fluid reservoir in which the outer circumferential portion of the diaphragm is fitted and supported between the inner wall surface of the outer circumferential cylindrical portion of the cap and the upper outer circumferential wall surface of the reservoir body, a reservoir is attached to the upper outer circumferential wall of the reservoir body. There is a tapered surface that is uniform over the entire circumferential direction of the main body and that reduces the outer diameter of the reservoir main body as it goes toward the upper end surface of the reservoir main body. The diaphragm has a thick outer periphery that connects to the inner part and surrounds the periphery of the diaphragm, and the inner surface of the thick outer periphery of the diaphragm is tapered to fit the tapered surface of the reservoir body over the entire periphery of the diaphragm. This thick outer periphery is located entirely on the outer periphery side than the outer edge of the upper end surface of the reservoir body, and furthermore, the thick outer periphery is located inwardly along the upper end surface of the reservoir main body. A hydraulic fluid reservoir that has a structure in which a thin wall extending from the top of the reservoir body is supported by being sandwiched between the upper end surface of the reservoir body and the cap.