JP2001260865A - Brake operating device and its component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake operating device with a master cylinder and a pressure booster combined, ensuring prevention of the entry of foreign matters and a water around a piston in a master cylinder without increasing the numbers of parts and assembling processes and complicating the construction. SOLUTION: The brake operating device, wherein part of a base cap 14 of the master cylinder 10 is fitted to a recessed portion 75 of a front shell 41 of the pressure booster 40, the piston 16 is extended from the base cap 14 to a negative pressure chamber 49, passing through the bottom of the recessed portion 75, and an output shaft 73 is connected thereto, comprises a seal ring 80 fixedly arranged in the recessed portion 75, with a main lip portion 82 contacting the piston 17 and a sub-lip portion 83 contacting the base cap 14, so that the sub-lip portion 83 is used to restrict foreign matters and a water from entering around the piston 16 from the outside and carry a leaked oil due to the defect of the master cylinder 10 from the sub-lip portion 83 through a cutout groove 85 at the end of the seal ring 80 to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular brake operating device in which a master cylinder and an air pressure booster are combined, and a component thereof.

[0002]

2. Description of the Related Art Recently, in order to reduce a mounting space in a vehicle, a brake operating device of this kind is used as a master cylinder 1 as shown in FIG. The piston 3 of the master cylinder 1 is inserted through the bottom of a concave portion 6 provided in the front shell 5 of the pneumatic booster 4 and a negative pressure is applied. In many cases, the structure extends to the inside of the chamber R, and the output shaft 7 of the pneumatic booster 4 is operatively connected to the piston 3 in the negative pressure chamber R. In this case, in order to maintain airtightness in the negative pressure chamber R of the pneumatic booster 4, conventionally, a seal ring 9 is provided in the recess 6 of the front shell 5 by using a retainer 8.
Is immovably fitted, and a lip 9a provided on the inner periphery of the seal ring 9 is slidably contacted with the piston 3. Reference numeral 5a denotes an oil groove for allowing oil leaking from the mouth of the master cylinder 1 to flow out.

[0003]

According to the conventional sealing structure using the seal ring 9, however, although the airtightness in the negative pressure chamber R of the pneumatic booster 4 can be maintained, the airtightness is higher than that of the seal ring 9. Casing 2 of cylinder 1
The portion of the piston 3 located on the side is exposed to the outside, so that foreign matter or moisture may enter the portion from the outside, and the piston 3 may be scratched or corroded. .

As a countermeasure, a packing P may be sandwiched between the rear end of the casing 2 of the master cylinder 1 and the front shell 5 of the pneumatic booster 4, as shown in FIG. However, in this case, there is a problem that the cost burden increases because the number of parts and the number of assembly steps are unavoidable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to reduce the number of parts and the number of assembling steps without increasing foreign matter and moisture around the piston of the master cylinder. It is an object of the present invention to provide a vehicular brake operating device and its components that can reliably prevent the intrusion of the vehicle.

[0006]

In order to achieve the above object, a brake actuating device according to the present invention comprises a combination of a master cylinder and a pneumatic booster, and the master cylinder extends from the rear end of its casing. The ejected piston extends through the front shell of the pneumatic booster into the negative pressure chamber, and is operatively connected to the output shaft of the pneumatic booster. In the brake operating device sealed by a seal ring, the seal ring comes into contact with the casing of the master cylinder to prevent foreign matter, moisture, and the like from entering the periphery of the piston from outside, and to prevent leakage of oil leaking from the master cylinder. And a lip portion that allows outflow to the device. In the vehicle brake operating device configured as described above, the lip portion provided on the seal ring suppresses intrusion of foreign matter, moisture, and the like from the outside around the piston, so that a special member (packing) for suppressing such intrusion is unnecessary. become.

In the brake operating device, a notch may be provided in a lower portion of the lip portion of the seal ring when the vehicle is mounted, so that oil leaking from the mouth of the master cylinder to the outside can be provided. Outflow is easier.

In the brake operating device, the seal ring is disposed in a concave portion provided in a front shell of the pneumatic booster, and a tip of a cylindrical main body extending to the master cylinder side is attached to the master cylinder. The position may be fixed by abutting the rear end of the casing, so that a special member (retainer) for fixing the position of the seal ring becomes unnecessary.

The seal ring according to the present invention is interposed at the joint between the master cylinder and the pneumatic booster. The seal ring contacts the piston of the master cylinder on the inner peripheral side of the cylindrical main body. It is characterized in that a first lip portion and a second lip portion that contacts the outer surface of the casing of the mast cylinder are provided. The present invention may be configured as a single master cylinder equipped with such a seal ring. In this case, the seal ring is fitted on a piston extending from the rear end of the casing. .

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 8 show one embodiment of a brake operating device according to the present invention. The overall structure of the brake actuator is the same as that shown in FIG.
0, a tandem pneumatic booster 40, and a seal ring 80 interposed between the master cylinder 10 and the pneumatic booster.

As shown in FIG. 7, the tandem type master cylinder 10 uses a casing body 12 having a bottomed hole (stepped hole) 11 and a ring screw 13 at an open end of the casing body 12. A casing 15 comprising a mouth cap 14 covered with a cover is provided. In the casing 15, an assembly sleeve 18 for slidingly guiding the two pistons 16 and 17 is accommodated. The assembly sleeve 18 includes a sleeve main body 19 and two ring guides 20, 2 disposed at both ends of the sleeve main body 19.
1, which includes each ring guide 20,
21 slidably contact the pistons 16 and 17 at both ends, between the two pistons 16 and 17, and the piston 1 on the back side.
Between the pressure chamber 7 and the bottom of the hole 11, respectively.
A pair of seal cups 24 and 25 that define and define each of the seal cups 3 are held.

Of the two pistons, the piston (first piston) 16 on the opening end side of the hole 11 is the casing 1
The rear end 16a extends to the outside of the casing by passing through the bottom of the mouth cap 14 constituting the rear end portion 5 and the rear end 16a is inserted into a pneumatic booster 40 described later in detail. It has become.

The first piston 16 has a cup-shaped portion 1 whose front end, which is the side of the casing body 12 to be inserted into the hole 11.
6b, the one pressure chamber (first pressure chamber) 2
2, the cup-shaped portion 16b of the first piston 16
Of the cup bottom and the piston at the back of the hole 11 (second piston)
13, a first return spring 27 for engaging both ends with the rear end,
It is arranged using an extendable spring receiver 26. On the other hand, the second piston 17 has a cup shape as a whole, and the second pressure chamber (second pressure chamber) 23
A second return spring 28 that engages both ends with the cup bottom of the piston 17 and the bottom of the hole 11 is provided. The spring force of the first return spring 27 is set to be larger than the spring force of the second return spring 28. Therefore, when the first piston 16 advances to the bottom surface side of the hole 11, the movement is changed to the first return spring 2
The second piston 17 is transmitted to the second piston 17 through the second spring 7 and contracts the second return spring 28 to move forward. The first pressure chamber 22 is provided with the sleeve body 19.
A first pipe port 30 connected to a system of wheel cylinders (not shown) through an axial groove 29 provided on the inner peripheral surface of the first pipe 30
On the other hand, the second pressure chamber 23 is opened with a second piping port 31 that is connected to another type of wheel cylinder by piping, and the first and second pistons 16 and 17 are moved in accordance with the advance of the first and second pistons 16 and 17. The oil liquid (brake liquid) sealed in each of the pressure chambers 22 and 23 is pressure-fed to a corresponding wheel cylinder.

Reference numeral 32 denotes a reservoir connected to the casing 15. Two ports 33 and 34 communicating with the reservoir 32 are provided on the upper wall of the casing body 12 so as to be spaced apart from each other in the axial direction. An axial groove 35 communicating with one port 33 is formed on the outer peripheral surface of the sleeve main body 19, and a radial hole 36 communicating with the axial groove 35 is formed on one ring guide 20. I have. A radial hole 37 communicating with the other port 34 is formed in the other ring guide 21, and the distal end of the cup-shaped portion 16 b of the first piston 16 and the second piston 1
A plurality of through-holes 38 and 39 are provided at the tip of 7 and are equally arranged in the circumferential direction. In a state where the first and second pistons 16 and 17 are positioned at the original positions shown in the drawings, the through holes 3 formed in the pistons 16 and 17 are formed.
8, 39 slightly wrap around the radial holes 36, 37 of each said ring guide 20, 21 so that from the reservoir 32 via each port 33, 34, the radial holes 36, 37 and the through holes 38, 39. , First and second pressure chambers 22,
23 is supplied with brake fluid.

As shown in FIG. 8, the tandem type pneumatic booster 40 includes a shell body 43 including a front shell 41 and a rear shell 42. The inside of the shell body 43 is moved forward and backward by a center shell 44. It is divided into two chambers, and the front and rear two chambers are further divided into diaphragms 45 and 46.
Are divided into constant-pressure chambers (negative-pressure chambers) 49 and 50 and working-pressure chambers 51 and 52 by power pistons 47 and 48 provided with. A hollow valve body 53 arranged on the axis of the shell body 1 is fitted and supported by each of the power pistons 47 and 48. The valve body 53 hermetically and slidably moves the center shell 44 and the rear shell 42. The small diameter portion 53a on the rear end side extends freely to the rear of the rear shell 42.

The valve body 53 has two negative pressure chambers 49.
And a negative pressure passage 54 communicating the negative pressure chambers 49 and 50 to the inside of the valve body 53, and communicating the two operating pressure chambers 51 and 52 and each operating pressure chamber 51,
An air passage (atmospheric passage) 55 that connects the valve body 52 to the inside of the valve body 53 is provided. For example, an engine negative pressure is introduced into the negative pressure chamber 49 on the front side, while the atmosphere is introduced into the small diameter portion 53 a of the valve body 53 through the silencer 56 and the filter 57. ing.

In the valve body 53, the negative pressure passage 54 and the atmospheric passage 55 are provided for the front and rear working pressure chambers 51 and 52.
A valve mechanism 58 and a reaction force adjusting mechanism 59 for selectively opening the same are internally provided. The valve mechanism 58 includes a plunger 61 operatively connected to an input shaft 60 interlocked with a brake pedal (not shown), and an elastically deformable valve having a base end fixed to an inner surface of the valve body 53 using a pressing member 62. The valve body 63 and the valve body 63 are normally seated on an annular negative pressure valve seat portion 64 formed on the inner periphery of the valve body 53 and an annular atmospheric valve seat portion 65 formed on the rear end of the plunger 61. And a valve spring 66 that urges the valve spring 66 in a predetermined direction. In the valve body 53, there is provided a return spring 67 interposed between the input shaft 60 and the pressing member 62 and normally biasing the input shaft 60 in the return direction. Also, the reaction force adjusting mechanism 59
Is a reaction force receiver 6 disposed on the front end side of the valve body 53.
8, a hat-shaped spring receiver 69 arranged in contact with the plunger 61, a compression spring 70 interposed between the spring receiver 69 and the reaction force receiver 68, and a compression spring 7
And an adjustment rod 71 for adjusting the set load of zero.

On the other hand, in the center of the front end of the valve body 53, a reaction disk 7 made of an elastic material such as rubber is provided.
2, the base large-diameter portion 73a of the output shaft 73 is operatively connected. In the negative pressure chamber 49 on the front side, a return spring 74 for returning the valve body 53 to the original position is provided. The return spring 74 is connected to the front shell 41.
Is provided between the rear side of the step portion 75a in the concave portion 75 provided on the front surface of the valve body 53 and the inner diameter step portion 53a provided on the valve body 53. Further, a proximal output shaft 73 of the output shaft 73 is provided on the inner diameter step 53a of the valve body 53.
A hat-shaped pressing member 76 for retaining the “a” is locked, and the position of the pressing member 76 is fixed by the return spring 74.

The pneumatic booster 40 has a plurality of stud bolts 77 erected on the rear surface of the rear shell 42.
On the other hand, the pneumatic booster 40 is attached to the vehicle body using mounting bolts 78 (FIG. 8) erected on the front surface of the front shell 41.
Are combined. The connection of the master cylinder 10 to the pneumatic booster 40
5 is fitted into the concave portion 75 of the front shell 41, and the first piston 16 extending from the proximal cap 14 is inserted through the concave portion 75 so that the pneumatic booster 40 In this connection state, the output shaft 73 of the pneumatic booster 40 is inserted into a hole 79 provided in the rear end 16a of the first piston 16. The first piston 16 comes into contact with the bottom of the hole 79 of the first piston 16. In this connection, the seal ring 80 is also held in the recess 75 of the front shell 41 between the master cylinder 10 and the pneumatic booster 40 in the axial direction of the piston 16 and the output shaft 73. Be placed.

As shown in FIGS. 3 and 4, a seal ring 80 is provided on the inner peripheral side of a cylindrical main body 81.
The main lip portion 82 that contacts the first piston 16 of the master cylinder 10 and the mouth cap 14 of the master cylinder 10
And a sub-lip portion 83 that contacts the outer surface of the main body at a predetermined interval. The main body 81 is provided with the pneumatic booster 4.
In the state where the master cylinder 10 is coupled to the front shell 41, the distance between the surface of the step portion 75a in the concave portion 75 of the front shell 41 and the surface of the step portion (rear end) 14a of the mouth cap 14 is slightly larger. The length (height) is set, and the seal ring 80
Is to bring the base end of the main body 81 into close contact with the step portion 75a in the concave portion 75 of the front shell 41, and to contact the front end of the main body portion 81 with the step portion (rear end) 14a of the mouth cap 14. The position is fixed. That is, the seal ring 80 is configured such that the base end of the main body portion 81 is brought into close contact with the front shell 41 and the main lip portion 82 is brought into sliding contact with the first piston 16 of the master cylinder 10, whereby the pneumatic booster 40 is provided. The negative pressure chamber 49 is kept airtight, and the sub lip 83 is brought into contact with the outer surface of the lip cap 14 of the master cylinder 10, so that the second lip 83 is exposed between the lip cap 14 and the main lip 82. The air space 84 around one piston 16 is closed from the outside.

In this case, the main and sub lip portions 82 and 83 of the seal ring 80
0, so that the diameter gradually decreases in the in-axis direction.
Fluid (leakage oil) flowing out of the device is allowed to some extent. The seal ring 80 is also provided with a plurality of cutout grooves 85 at the tip end of the main body portion 81, which is on the side that comes into contact with the step portion 14a of the mouth cap 14, and is equally arranged in the circumferential direction. This notch groove 85 is formed in the air space 84.
3 and 4, and has a considerably wide width as shown in FIGS. 3 and 4, or at 85 'in FIGS. 5 and 6. As shown, it may be provided with a considerably narrow width. Note that a reinforcing insert 86 (FIG. 2) is embedded in the base end of the seal ring 80.

Hereinafter, the operation of the brake operating device configured as described above will be described. The above-described pneumatic booster 40
Is mounted on the vehicle body using the plurality of stud bolts 77 erected on the rear surface of the rear shell 42 as described above. In this mounted state, a brake pedal (not shown) is connected to the input shaft 60. When the brake pedal is depressed in this mounted state, the input shaft 60 moves forward, the plunger 61 moves, the negative pressure valve seat 65 opens, and air flows into the valve body 53 through the silencer 56 and the filter 57. This atmosphere is introduced into two working pressure chambers 52 and 51 through an atmosphere passage 55. As a result, a differential pressure is generated between the negative pressure chambers 49 and 50 into which the negative pressure is introduced and the working pressure chambers 51 and 52, and the front and rear power pistons 47 and
8 advances and an output of a predetermined boosting ratio is transmitted to the output shaft 73 via the valve body 53, and a boosting action is performed.

The output of the output shaft 73 of the pneumatic booster 40 is transmitted to the first piston 16 of the master cylinder 10, and the first piston 16 and the second piston 17 compress the second return spring 28. Move forward together. Then, as the pistons 16 and 17 advance, the respective through holes 38 and 39 first move forward of the corresponding seal cups 24 and 25, and the first and second pressure chambers 22 and 23 and the reservoir 32 are connected. The communicating flow path is shut off. As a result, the first,
The fluid pressure in the second pressure chambers 22 and 23 increases, and this pressure fluid is supplied from the first and second piping ports 30 and 31 to the wheel cylinders of each system, and predetermined braking is performed. At this time,
While the input is small, the output reaction force is applied to the output shaft 73 of the pneumatic booster 40 from the first piston 16 of the master cylinder 10.
Through the reaction disk 72, and further through the reaction force adjusting mechanism 59 and the plunger 61.
During this time, a boosting action is performed in which the output increases as the input increases. The input is the reaction force adjusting mechanism 5
When the load exceeds the set load of the compression spring 70, the gap between the reaction force receiver 68 and the spring receiver 69 is eliminated. During this time, a jump-in output is generated, and a large output, that is, a braking force is obtained.

On the other hand, when the depression force on the brake pedal is released, the two pistons 17, 16 are integrally retracted by extension of the second return spring 28 in the master cylinder 10, and return to the original positions shown in FIGS. I do. At this time, if the return liquid to the first and second pressure chambers 22 and 23 is insufficient, the reservoir 32
The oil liquid in the inside is supplied to the first and second pressure chambers 22 and 23 from the two ports 33 and 34 through the respective flow paths corresponding thereto. On the other hand, when the pistons 17 and 16 are retracted, the input shaft 60 in the pneumatic booster 40 is retracted by the restoring force of the return spring 67, and the plunger 61 is also retracted.
While the valve seat 65 for the atmosphere is closed, the valve seat 64 for the negative pressure is opened, and a negative pressure is introduced into the two working pressure chambers 52 and 51 via the negative pressure passage 54, so that the above-mentioned differential pressure is eliminated. Thereafter, the valve body 53 is retracted by the spring force of the return spring 74 in the negative pressure chamber 49 on the front side, and the power pistons 47 and 48 return to their original positions.

In the brake actuating device constructed and operated as described above, the auxiliary lip portion 83 provided on the seal ring 80 is provided with an air space 84 around the first piston 16 from the outside.
Since the intrusion of foreign matter, moisture, and the like into the air is suppressed, the packing P (FIG. 12) for suppressing the invasion of the foreign matter becomes unnecessary, and the master cylinder 10 and the pneumatic booster 40 are accordingly reduced.
Can be easily assembled. Particularly in the present embodiment, the height of the main body portion 81 of the seal ring 80 is sufficiently large, and the front end thereof is in contact with the rear end of the mouth cap 14 constituting the casing 15 of the master cylinder 10.
The retainer 8 (FIG. 12) for fixing the position, which has been indispensable in the past, is also unnecessary, and the assembly of the master cylinder 10 and the pneumatic booster 40 becomes easier. In this case, the seal ring 80 is fitted in advance to the first piston 16 of the master cylinder 10 as shown in FIG. 7, or the front shell 41 of the pneumatic booster 40 as shown in FIG. By fitting the seal ring 80 into the recess 75, the master cylinder 10
Just press the casing 15 of the seal ring 80
Is positioned at a predetermined position, so that the assembly of the master cylinder 10 and the pneumatic booster 40 is extremely easy.

Also, even if oil leaks from the mouth of the master cylinder 10, the oil leaks from the seal ring 80.
Pushes the sub lip 83 of the back from behind and flows forward,
Further, the oil flows out of the oil groove 41a provided in the front shell 41 of the pneumatic booster 40 through the notch groove 85 (85 ') on the distal end side of the main body portion 81, so that the master cylinder 10 is lost. It can be detected reliably. Particularly, in the present embodiment, the auxiliary lip portion 83 of the seal ring 80 is formed to have a shape whose diameter is gradually reduced in the axial direction of the master cylinder 10, so that the leakage of the leaked oil from the mouth of the master cylinder 10 to the outside becomes more difficult. It will be easier.

Here, the air space 8 around the first piston 16
Since foreign matter, moisture, and the like do not enter the vehicle from the lower side when the brake operating device is mounted on the vehicle, as shown in FIGS. A cutout groove 90 may be provided in a lower portion of the vehicle 83 when the vehicle is assembled, so that leakage of leaked oil from the mouth of the master cylinder 10 to the outside is promoted.

The oil groove 41a of the front shell 41 of the pneumatic booster 40 can be omitted. In this case, it is not necessary to perform special processing on the front shell 41, which is advantageous in terms of cost. Become. Further, in the above embodiment, a tandem type booster is used as the pneumatic booster 40. However, the type of the pneumatic booster is arbitrary, and it goes without saying that a non-tandem type may be used. It is.

[0029]

As described above, according to the brake operating device and the components thereof according to the present invention, the number of parts and the number of assembling steps are not increased, and the structure of the master cylinder is not increased. Intrusion of foreign matter and moisture around the piston can be reliably prevented, which greatly contributes to improvement in productivity and reduction in manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall structure of a brake operating device according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a structure of a connecting portion between a master cylinder and a pneumatic booster constituting the brake operating device.

FIG. 3 is a cross-sectional view showing a structure of a seal ring used in the brake operating device.

FIG. 4 is a plan view of the seal ring shown in FIG.

FIG. 5 is a sectional view showing another structure of the seal ring used in the brake operating device.

FIG. 6 is a plan view of the seal ring shown in FIG.

FIG. 7 is a sectional view showing a structure of a master cylinder constituting the brake operating device.

FIG. 8 is a cross-sectional view showing the structure of a pneumatic booster constituting the brake operating device.

FIG. 9 is a cross-sectional view illustrating a main structure of a brake operating device according to another embodiment of the present invention.

FIG. 10 is a sectional view showing a structure of a seal ring used in the brake operating device shown in FIG. 9;

11 is a plan view of the seal ring shown in FIG.

FIG. 12 is a cross-sectional view showing a main structure of a conventional brake operating device.

[Explanation of symbols]

 Reference Signs List 10 master cylinder 12 casing body 14 mouth cap 15 casing 16 first piston 17 second piston 18 assembly sleeve 22, 23 pressure chamber 32 reservoir 40 pneumatic booster 41 front shell 47, 48 negative pressure chamber 53 valve body 58 valve mechanism 73 Output shaft 80 Seal ring 81 Seal ring main body 82 Main lip 83 Sub lip (lip) 85, 85 'Notch groove in main body 90 Notch groove in sub lip

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shuzo Watanabe 1000 Koda-machi Yoshida, Nakakoma-gun, Yamanashi Pref.

Claims (5)

[Claims] 1. A master cylinder comprising a combination of a master cylinder and a pneumatic booster, wherein the master cylinder has a piston extending from a rear end of a casing thereof inserted through a front shell of the pneumatic booster to form a negative pressure chamber. A brake actuating device, which is operatively connected to the output shaft of the pneumatic booster, wherein the seal between the front shell and the piston is sealed by a seal ring.
A lip portion is provided which is in contact with the casing of the master cylinder, prevents intrusion of foreign matter, moisture, and the like from the outside around the piston, and allows leakage of oil leaking from the master cylinder to the outside. Brake actuator for vehicles. 2. The vehicle brake operating device according to claim 1, wherein a notch is provided in a lower portion of the lip portion of the seal ring when the vehicle is mounted. 3. A seal ring is disposed in a recess provided in a front shell of the pneumatic booster, and a distal end of a cylindrical body extending toward the master cylinder abuts on a rear end of a casing of the master cylinder. The vehicle brake operating device according to claim 1 or 2, wherein the position is fixed. 4. A seal ring interposed in a joint portion between a master cylinder and a pneumatic booster, wherein a first ring is provided on an inner peripheral side of a cylindrical main body portion and in contact with a piston of the master cylinder.
A seal ring comprising a lip portion and a second lip portion that contacts a casing outer surface of a master cylinder. 5. A master cylinder, wherein the seal ring according to claim 4 is fitted to a piston extending from a rear end of the casing.