JPH0539979Y2 - - Google Patents

Description

[Detailed description of the invention] a. Field of industrial application The present invention relates to a fluid actuator in which a master cylinder and a booster are fastened to each other, and more specifically, it relates to a fastening structure between the master cylinder and the booster. .

b. Prior Art Figure 9 shows a tandem master cylinder 1 as a main part of a fluid actuator using a piston.
This is what is shown. This master cylinder 1 has a housing 2 with one end open, and inside this housing 2, a tip 3a of a primary piston 3 and a secondary piston 4 are slidably disposed via piston guides 5a and 5b. ing.
A first pressure chamber 7a is formed inside the housing 2 by the primary piston 3 and a sleeve 6 disposed between the piston guides 5a and 5b, and a first pressure chamber 7a is formed inside the housing 2 by the secondary piston 4 and the inner wall surface of the housing 2. A second pressure chamber 7b is formed by the above. Further, spring mechanisms 8a and 8b are provided in the first pressure chamber 7a and the second pressure chamber 7b, respectively. A cap 9 is screwed onto the open end of the housing 2, and the cap 9 closes one end of the opening of the housing 2.

In such a master cylinder 1, with the rear end 3b of the primary piston 3 inserted into the booster 11, the cap 9 side is fastened with bolts and nuts, and the output rod (not shown) of the booster 11 is fastened to the cap 9 side with bolts and nuts. ) is inserted into the rear end recess 3c of the primary piston 3. As a result, the leftward movement of the output rod pushes the primary piston 3 and the secondary piston 4 in the same direction, and the compressed fluid (hydraulic fluid) in the first and second pressure chambers 7a and 7b is supplied to the brake system. It is configured so that it can be fed under pressure, etc.

c Problems that the invention attempts to solve However, master cylinder 1 and booster 1
In the case of a conventional fluid actuator (so-called master cylinder with booster), in which caps 1 and 1 are fastened to each other, no measures are taken to prevent the cap 9 from loosening, and the cap 9 is susceptible to heat aging, vibration,
There was a risk that the screws of the cap 9 would come loose due to impact loads, etc. Further, there was also a risk that foreign substances such as water and oil could enter the interior through the connection between the master cylinder 1 and the booster 11.

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to provide a liquid actuator configured to reliably prevent the master cylinder cap from loosening and also to prevent foreign matter from entering. It's about doing.

d Means for Solving the Problems In order to achieve the above object, the present invention provides a fluid actuator in which a master cylinder and a booster are fastened to each other, in which the housing is closed to close an end opening of the housing of the master cylinder. A ring-shaped elastic member is fitted into a cap that is screwed onto the cap, and the outer circumferential portion of the elastic member is interposed between the housing and the booster to sandwich it, thereby sealing the space between the housing and the booster. In addition, by attaching the inner peripheral side portion of the elastic member which is held between them and prevented from rotating, to the cap, the elastic member and the cap are configured to be relatively prevented from rotating. are doing.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 shows a fluid actuator to which the present invention is applied, and this fluid actuator is composed of a master cylinder 10, a booster 11 and an oil reservoir 12 fastened to the master cylinder 10.

One end of the housing 10a of the master cylinder 10 is open, and a cap 13 is screwed onto the housing 10a to close this opening. Note that the portion indicated by the symbol A in FIGS. 1 and 2 is the screwed portion of the cap 13 onto the housing 10a. Ring-shaped piston guides 14 and 15 are disposed within this housing 10a, and these piston guides 14 and 15 have a primary piston 16 and a secondary piston 17.
are inserted in each. And, by the piston guide 15 and the secondary piston 17,
The inside of the housing 10a is defined into two pressure chambers 18 and 19. The above-mentioned pistons 16 and 17 are
They are each guided also by a sleeve 20 arranged in the pressure chamber 18 . That is, this sleeve 20 has an inner peripheral surface formed in a spline shape in order to secure a space for the pressure chamber 18.
The pistons 16, 17 are guided by the protruding portions 20a. Moreover, the above-mentioned pistons 16 and 17 are
The first
In the figure, it is energized to the right. These pistons 16 and 17 have a recess opening at the tip, and through holes 23 and 24 are formed in the peripheral wall forming the recess.
are drilled in each. The piston guides 14 and 15 have holes 25 and 2 in the radial direction.
6 are bored, one end of these holes 25, 26 opens to the sliding surfaces of the pistons 16, 17, and the other end opens to passages 27, 28 formed in the housing 10a.
is communicated with.

Note that the oil reservoir 12 is connected to the housing 10.
Passages 29 and 30 fixedly installed in the housing 10a and bored at the bottom of the oil reservoir 12 communicate with passages 27 and 28 of the housing 10a, respectively. Also,
Reference numerals 31 and 32 indicate holes formed in the cylinder housing 10a, and the pressure chambers 18 and 19 communicate with an actuated device (not shown), such as a wheel cylinder, through these holes 31 and 32.

On the other hand, the booster 11 is integrally fastened to the end surface of the master cylinder 10 on the cap 13 side at a plurality of locations using fastening means using bolts 33a and nuts 33b. As a result, the tip 16a of the primary piston 16 protruding from the cap 9
is arranged inside the booster 11, and an output rod (not shown) of the booster 11 is fitted into the recess 16b of the tip 16a.

By the way, in this embodiment, the sealing performance between the master cylinder 10 and the booster 11 is improved,
In addition, in order to prevent the cap screws from loosening, an annular elastic member 34 is attached to the outer periphery of the cap 13 between the master cylinder 10 and the booster 11, as shown in FIGS. 1 and 2. has been done. That is, as clearly shown in FIGS. 2 and 3, the elastic member 34 has an outer peripheral surface 34a formed as a cylindrical surface, and a fitting portion 13a of the cap 13 formed in a regular hexagonal shape is inserted into the elastic member 34. The center fitting hole 34b is formed into a regular hexagonal shape corresponding to the shape of the fitting hole 13a of the cap 13. Thus, the outer circumferential portion of the annular elastic member 34 is sandwiched between the housing 10a of the master cylinder 10 and the booster 11 and is disposed as a sealing member, and the inner circumferential portion of the elastic member 34 is inserted into the fitting hole 34b. The fitting portion 13a of the cap is assembled in a relatively fitting arrangement. Furthermore, the size of the fitting hole 34b of the elastic member 34 is formed to be slightly larger than the size of the fitting part 13a of the cap 13, so that the size of the fitting hole 34b of the fitting hole 13a is slightly larger than that of the fitting part 13a of the cap 13. Insertion can be performed smoothly, and the structure is such that relative rotation between the two is prevented after fitting. The fitting portion 13a and the fitting hole 34b may have any shape as long as they prevent relative rotation (for example, a square, a pentagon, a rhombus, etc.).

Next, the operation of the above-described fluid actuator will be explained with reference to FIGS. 4 and 5. however,
In FIGS. 4 and 5, the primary piston 1
6. Only the piston guide 14, etc. are shown, but the secondary piston 17, piston guide 15, etc. perform the same function, so their explanation will be omitted here.

FIG. 4 shows the piston 16 in its inactive state, that is, in its standby state. In this state, the through hole 23 of the piston 16 is connected to the hole 23 of the piston guide 14.
5, and the pressure chamber 18 is located in the center of the through hole 2.
3, oil reservoir 1 via hole 25 and passage 27
It is connected to 2. Therefore, in this state, compressed fluid (hydraulic pressure) is not acting on the actuated device (not shown).

Under such conditions, when the piston 16 is pushed inside the pressure chamber 18, the through hole 23 also moves to the left as shown in FIG.
1 to an actuated device (not shown).

As described above, according to the fluid actuator of this embodiment equipped with the annular elastic member 34, the elastic member 34 is provided between the master cylinder 10 and the booster 11.
Since the elastic member 34 is tightened and fixed with the bolt 33a and nut 33b with the outer circumferential side of the elastic member 34 interposed therebetween, the outer circumferential side of the elastic member 34 serves as a sealing member for these two parts.
For this reason, it is possible to prevent foreign matter such as water or oil from entering the inside through the fastening portion of both parts.

Furthermore, the housing 10 of the master cylinder 10
The cap 13 of the master cylinder 10 is fitted into the fitting hole 34b of the inner circumference side portion of the elastic member 34 which is clamped and fixed between the booster 11 and the booster 11, with the cap 13 of the master cylinder 10 being relatively prevented from rotating. Therefore, the engagement between them reliably prevents the cap 13 from rotating relative to the housing 10a, and as a result, there is no possibility that the screw fixation of the cap 13 will loosen. It disappears.

Although one embodiment of the present invention has been described above, the present invention is not limited to the embodiment described above, and various modifications and changes can be made based on the technical idea of the present invention.

For example, as shown in FIG. 6, when the shape of the cap 13 is cylindrical, recesses 36a and 36b are formed in opposing portions of the cap 13, and the elastic member 34 is fitted correspondingly to the recesses 36a and 36b. Matching hole 3
4b is made into a cylindrical shape, and convex portions 37a, 37b are formed at locations facing each other, and the convex portions 37a,
The elastic member 34 may be attached to the cap 13 with the elastic member 37b engaged with the recesses 36a and 36b. As shown in FIG. 7, protrusions 38a and 38b are formed on the side of the cap 13, and correspondingly protrusions 39a and 39a are formed on the side of the elastic member 34.
9b may be formed.

Further, as shown in FIG. 8, an annular elastic member 3
A recess 40 is formed in the recess 40, and the outer peripheral edge of the metal ring member 42 is fitted into the recess 40.
While inserting the connecting piece 34a of the elastic member 34 into the through hole 42a formed in the ring member 42,
Projection piece 42b provided on the inner peripheral side of ring member 42
into the recess 36b of the cap 13,
It is also possible to prevent the cap 13 from rotating.

e Effects of the Invention As described above, the present invention provides a seal between the housing and the booster by interposing and sandwiching the outer peripheral side portion of the elastic member between the housing of the master cylinder and the booster. By attaching the inner circumference side portion of the elastic member which is held between the housing and the cap screwed to the housing, the elastic member and the cap are relatively prevented from rotating. Therefore, the cap of the master cylinder is prevented from rotating relative to the elastic member fixed between the housing and the booster.
It is possible to reliably prevent the occurrence of inconveniences such as the cap screws loosening due to rotation of the cap due to heat aging, vibration, impact load, etc.

Furthermore, since the outer circumferential portion of the elastic member is interposed at the joint between the master cylinder and the booster, this elastic member serves as a sealing member, allowing foreign substances such as water and oil to pass through the joint. Intrusion can be reliably prevented.

Furthermore, according to the present invention, not only can the seal between the master cylinder and the booster and the rotation prevention of the cap be achieved with one elastic member, but also the positional relationship of the attachment state (rotation position) of the cap with respect to the master cylinder. The cap can be prevented from rotating regardless of the rotation.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, in which Figure 1 is a configuration diagram of a fluid actuator, and Figure 2 shows an elastic member held between a master cylinder and a booster. A sectional view, FIG. 3 is a front view showing how the elastic member is fitted into the cap, and FIG.
6 and 7 are front views similar to FIG. 3 showing modified examples of the elastic member and the cap, respectively. 9 is a sectional view showing a modification of the cap rotation prevention structure, and FIG. 9 is a sectional view of a master cylinder forming a part of a conventional fluid actuator. 10... Master cylinder, 10a... Housing, 11... Booster, 12... Oil reservoir, 13... Cap, 33a... Bolt, 33
b... Nut, 34... Annular elastic member, 34a
...outer peripheral surface, 34b...fitting hole, 41...fitting hole, 42...metal ring member, A...screwing part.

Claims (1)

[Scope of utility model registration request] In a fluid actuator in which a master cylinder and a booster are fastened to each other, an annular elastic member is fitted into a cap screwed onto the housing to close an end opening of the housing of the master cylinder, and the housing and the booster are connected together. By sandwiching the outer circumferential side of the elastic member between them, a seal is created between the housing and the booster, and the inner circumferential side of the elastic member that is sandwiched between them and prevented from rotating. A fluid actuator characterized in that the elastic member and the cap are relatively prevented from rotating by attaching the elastic member to the cap.