JPH0611842Y2 - Tandem booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a tandem booster used for a brake device of a vehicle or the like, and more particularly, to a plate in which a pressure receiving portion inside a casing fits around an outer periphery of a hub portion, The present invention relates to a technique effective in stably supporting a plate when the plate is constituted by a diaphragm supported by the plate.

(Prior Art and Problems Thereof) Generally, in a tandem booster, two internal cavities on a front side and a rear side are partitioned by a partition wall inside a main body that is a casing, and each of the internal cavities is divided into two internal cavities. A pressure receiving portion is formed. Therefore, the tandem booster has a larger pressure receiving area and a larger boosting function than a normal single type booster having one pressure receiving section.

However, on the other hand, since there are two pressure receiving portions in the axial direction, the tandem booster tends to have a complicated mounting structure for the components constituting each pressure receiving portion, and also tends to increase the axial space. In this respect, Japanese Patent Publication No. 62-20940 or Japanese Utility Model Application Laid-Open No. 57-98965 discloses that the main body of each pressure receiving portion on the front side and the rear side, or the main body of the pressure receiving portion on the front side and a part of the hub portion are formed by press molding. We propose a technology that simplifies the mounting structure of each pressure receiving part, which is composed of an integral part.

However, in those techniques, the return spring has to be provided in the inner diameter portion, and the effective pressure receiving area of each pressure receiving portion is reduced by the space of the return spring. Further, since the return spring itself is one, in order to obtain a predetermined return force and durability, the wire diameter of the spring and the number of effective turns increase, and the contact length and the free length increase.

Therefore, it is preferable to divide the return spring into two pieces and arrange each of the two coil springs in the chamber on the front side of the pressure receiving portion. Moreover, in that case, in consideration of assembling and handling of parts or weight saving of the hub portion, at least one of the two pressure receiving portions inside the casing is supported by the plate and the plate that fits on the outer periphery of the hub portion. It is better to configure with a diaphragm. For example, JP-A-60
No. 64058 discloses a technique based on that idea.

However, when the pressure receiving portion is composed of the plate and the diaphragm, how to stably support the plate with respect to the hub portion becomes a problem. When the return spring is divided into two, it is necessary to take measures against the problem.

In view of this, Japanese Patent Laid-Open No. 64058/1985 adopts a means of mounting a ring member for support on the outer periphery of the hub side. However, this requires extra parts and is troublesome in assembling.

(Purpose of the Invention) The present invention was made in consideration of the above points, and when the return spring is divided into two parts and the pressure receiving portion is formed by using the plate, the support of the plate is effectively stabilized. The purpose is to provide the technology to make it possible.

(Means for Solving the Problems) In this invention, as shown in FIG. 1 corresponding to the embodiment,
At least one of the pressure receiving portions 101 and 102 inside the casing, the plate 81 that fits on the outer periphery of the hub portion 50,
82, the diaphragm 71 supported by this plate,
It is assumed that it is composed of 72 and 72. Moreover,
The inner peripheral portions of the plates 81 and 82 are diaphragms 71 and 72.
While supporting the inner peripheral bead portion, the groove 5 on the outer periphery of the hub portion 50
31, 532, and at least a part of the inner peripheral portion of the plate is in contact with the front side wall surface of the grooves 531 and 532.
The support points of the end portions of the hubs 1, 92 are located radially outside of the outer circumference of the hub portion 50, and the inner circumferential portions of the plates 81, 82 also contact the outer circumference of the hub portion 50.
82c. Then, in order to stabilize the support of the plates 81 and 82, the positions of the plates 81 and 82 contacting the front side wall surfaces of the grooves 531 and 532 are viewed in the axial direction of the hub portion 50, and the guide shoulder portions 81c and 82c and the coil springs. 9
The plate 8 is located between the supporting points of the end portions of 1, 92.
Recesses 1 and 82 are formed to receive the ends of the coil springs 91 and 92.

(Operation thereof) The guide shoulders 81c and 82c are on the front side of the portions of the plates 81 and 82 that are in contact with the groove front side wall surfaces (the portions that exert a pressing force on the hub portion 50 during operation), and are the hubs of the plates 81 and 82. Radial movement with respect to the portion 50 is restricted.

On the other hand, the coil springs 91, 92 include the plate 81,
The end portion (support point) that abuts 82 enters a recess formed in the plates 81 and 82, and functions to restrict the radial movement of the plates 81 and 82 separately from the hub portion 50.

The ends (support points) of the coil springs 91, 92 on the plate 81, 82 side are located rearward of the portions of the plates 81, 82 in contact with the groove front side wall surfaces, so that the guide shoulders 81c, 82c are formed. In combination with restricting the radial movement of the hub portion 50, the portion that restricts the radial movement of the portion that exerts a pressing force on the hub portion 50 during operation is the hub portion 5
Seen in the axial direction of 0, it is extended substantially. in this way,
By increasing the location that regulates radial movement,
The plates 81 and 82 can be stably supported by the hub portion 50 even if a force acts such that the plates 81 and 82 move in the radial direction during operation.

(Example) The tandem booster 10 has the part of the main body 20 with a large diameter, and the protrusion part 30 which protruded from one rear side surface of the main body 20. The body 20 has a cup-shaped front shell 22.
And the dish-shaped rear shell 24 are joined together.
An internal space having a sufficient space is formed in the main body 20. On the other hand, the protruding portion 30 has a tubular portion 24a provided in the center of the rear shell 24 and a bellows-shaped boot 32 extending from the rear end of the tubular portion 24a.

The movable body 40 is arranged inside the main body 20 and the protruding portion 30. The main body of the movable body 40 is the hub portion 50 which is a plastic molded product. The hub portion 50 has a front portion 52 having a large diameter and a rear portion 54 having a small diameter. Movable body 40 or hub portion 50 which is the main body thereof
Can be moved in the front-rear direction while being guided and sealed by two parts, the outer periphery of the front part 52 and the outer periphery of the rear part 54. The guide ring 34 provided at the opening of the tubular portion 24a
A small diameter rear portion 54 is guided, and a lip 32a at the front end of the boot 32 seals around the rear portion 54. The large diameter front portion 52 is guided by the guide ring 36 provided on the inner circumference of the partition wall 60 and sealed by the seal ring 38. The partition wall 60 is a press-molded product and has a donut shape as a whole, and has cylindrical portions 61 and 63 extending in the axial direction on the inner peripheral side and the outer peripheral side, respectively. The end portion 61a of the cylindrical portion 61 on the inner peripheral side is bent in a direction orthogonal to the axis,
Thereby, the guide ring 36 is supported. On the other hand, the cylindrical portion 63 on the outer peripheral side is the front shell 2 of the main body 20.
A thin front shell 22 is reinforced along the inner surface of 2. The tubular portion 63 also supports the outer peripheral boards 71b and 72b of the respective diaphragms 71 and 72, which will be described later, and therefore the partition wall 60 divides the internal space of the main body 20 into the front side and the rear side. It's split in two.

The movable body 40 has, in addition to the hub portion 50, front and rear pressure receiving portions 101 and 102 that traverse the front and rear internal voids in the main body 20. Both pressure receiving parts 10
Reference numerals 1 and 102 have the same structure and are composed of plates 81 and 82 which are press-molded products, and diaphragms 71 and 72 which are supported by the plates 81 and 82. The large diameter front portion 52 of the hub portion 50 includes a groove 53 extending around each end near each end.
There are 1,532, respectively. These grooves 531 and 532 are
It is a groove into which the inner peripheral beads 71a, 72a of the diaphragms 71, 72 enter.

Each plate 81, 8 which is the bone of each pressure receiving portion 101, 102
2 is supported on the outer periphery of the large-diameter front portion 52 of the hub portion 50. Here, in order to support these plates 81, 82, the force of a return spring that gives a backward returning force to the movable body 40 is used. The return spring has two pressure receiving portions 101, 1
02 corresponding to 02, that is, the front coil spring 91 and the rear coil spring 92.

The coil springs 91, 92 use the biasing force also as the supporting force for the plates 81, 82, so that the receiving portions on the plates 81, 82 are arranged radially outside the outer circumference of the hub 50. Front coil spring 91
Is a spring bearing 93 applied to the inner wall surface of the front shell 22.
And the plate 81, and the rear side coil spring 9
2 are provided between the partition wall 60 and the plate 82, respectively. The diameters of the coil springs 91 and 92 are different from each other, and the coil springs 91 and 92 are concentrically arranged. Further, the plate 81 and the partition wall 60 have a recess 81 that overlaps each other when viewed in the radial direction.
There are d and 60d, and the ends of the coil springs 91 and 92 are inserted into the recesses 81d and 60d, respectively, which serve as support points. In this case, both of the coil springs 91 and 92 may be arranged inside, but as shown in the figure, when the coil spring 92 on the rear side is arranged inside, guiding of the inner diameter portion of the partition wall 60 is performed. The guiding action of the ring 36 becomes more stable.

Each of the plates 81, 82 has a folded-back portion 81a, 81b, 8 which is folded back inward so as to eliminate a gap at each end of the inner and outer circumferences.
2a, 82b, and folded-back portions 81a, 82a on the inner peripheral side
There are some bent portions including guide recesses 81c and 82c near the position, and a recess 81d on the outer peripheral side thereof. Each of these plates 81 and 82 has a guide shoulder 81.
c and 82c are fitted in the front side portions of the grooves 531 and 532 of the hub portion 50, and the end faces of the folded portions 81a and 82a have front side wall surfaces 531a and 532 of the grooves 531 and 532.
It is attached to the hub portion 50 side so as to engage with a. Each plate 81, 82 always receives a backward force from each coil spring 91, 92, which is a return spring, and the force is applied through the end portions of the guide shoulders 81c, 82c and the folded portions 81a, 82a. It is offset by the reaction force from the side. Therefore, although having a simple structure, the plates 81 and 82 are stably supported on the outer periphery of the hub portion 50. In particular, the plates 81, 82
The point of action of the force between the hub portion 50 and the hub portion 50 is located between the guide shoulder portions 81c and 82c and the support points at the ends of the coil springs 91 and 92 when viewed in the axial direction of the hub portion 50. ,
During the operation of the booster, the plates 81 and 82 are stably supported even when given a force that moves in the radial direction.

The plate portions 81 and 82 of the movable body 40, of course, cooperate with the diaphragms 71 and 72 to divide the two chambers into the front and rear internal voids in the main body 20. The front chambers 201f and 202f are constant pressure chambers, and the rear chamber 20 is
1b and 202b are transformer rooms. Both constant pressure chambers 201f, 2
02f passes through the first passage 111 provided in the hub portion 50, and both transformer chambers 201b and 202b pass through the second passage 1
12 communicate with each other. The constant pressure chambers 201f and 202f communicating with each other communicate with a negative pressure source such as an intake manifold of the engine through a joint portion 26 which is a connecting portion of piping and a hose (not shown) following the joint portion 26 and always maintain a negative pressure. On the other hand, the transformer room 201b, 20
2b is maintained at the same negative pressure as the constant pressure chambers 201f and 202f, or at the atmospheric pressure outside. Constant pressure chamber 201f,
202f and the variable pressure chambers 201b and 202b communicate with each other through, for example, the inner hole 56 of the hub portion 50 and two passages 57 and 58 that connect the inner hole 56 and each chamber when the brake is not operated. Both are held at a negative pressure by an external negative pressure source. However, when the brake is operated, the valve device 83 arranged inside the hub portion 50 operates in cooperation with the operating rod 84 which is an input member, and separates the two groups of chambers from each other. As a result, one of the constant pressure chambers 201f and 202f is still kept at the negative pressure, while the other of the variable pressure chambers 201b and 202b is kept at the atmospheric pressure by the outside air flowing through the filter 85. The force based on the differential pressure between the two groups of chambers is
In addition to the pedal effort, it is applied to the output member 87 side through the rubber disc 86.

Here, the rubber disk 86 and the large-diameter rear portion 87b of the output member 87 are fitted in the tubular member 88, and the stopper member 89 prevents the hub portion 50 from coming off. The tubular member 88 has a tubular portion 88a extending over the entire inner circumference thereof, and rib portions 88b radially provided on the outer peripheral surface of the tubular portion 88a. The rib portion 88b on the outer peripheral side forms a passage between adjacent ribs. Therefore, that portion can be utilized as a part of the passage provided in the hub portion 50. This point is effective in reducing the outer diameter of the hub portion 50.

The valve device 83 inside the hub portion 50 is well known in the art, and thus a detailed description thereof will be omitted. This valve device 83
It is the key member 90 that regulates the movement of the plunger 831 that constitutes a part of the. The key member 90 has a bifurcated leg portion from the outside of the hub portion 50 from the outside of the lateral hole 50 of the hub portion 50.
plug into a. The spring 120 provided between the key ring 90 and the stop ring 35 that stops the guide ring 34.
Regulates the return position of the plunger 831 through the key member 90, thereby reducing the ineffective stroke of the booster 10 in the initial operation. This spring 120
Are placed in the return position to form a close contact with each other to regulate the key member 90, and when the booster 10 operates, the key member 9
Free movement of 0.

(Effect of the Invention) According to this invention, when the return spring is divided into two coil springs 91 and 92, and at least one of the pressure receiving portions 101 and 102 is configured using the plates 81 and 82, Since the action points of the forces on the inner peripheral portions of 81 and 82 are set in a specific relationship, the support of the plates 81 and 82 can be effectively stabilized.

[Brief description of drawings]

FIG. 1 is a sectional structural view showing an embodiment of the present invention. 10 ... Tandem booster, 20 ... Main body, 40 ... Movable body, 50 ... Hub part, 60 ... Partition, 60a ... Recess, 71, 72 ... Diaphragm, 81, 82 ... Plate, 81a, Reference numeral 82a ... Fold-back portion, 81c, 82c ... Guide shoulder portion, 81d ... Recess, 84 ... Input member, 87 ... Output member, 91 ... Front coil spring, 92 ... Rear coil spring, 101 , 102 ... Pressure receiving part, 201f, 202f ... Constant pressure chamber, 201b, 202b ... Transformer chamber, 92 ... Output member.

Claims (2)

[Scope of utility model registration request] 1. A main body having a front side and a rear side internal space divided by a partition wall, a front side and a rear side pressure receiving portion that traverses each internal space, and both pressure receiving portions are supported. And a movable body each having a partition wall and a hub portion movably penetrating the rear side of the main body, a constant pressure chamber and a variable pressure chamber, each of which is divided into an inner space on the front side and the rear side by each pressure receiving portion, A first passage that connects between the constant pressure chambers in the internal space, a second passage that connects between the variable pressure chambers, a connecting portion that connects any of the constant pressure chambers to a negative pressure source, and the movable body are formed. A third passage for introducing outside air, an input member for entering the movable body from the outside, and a communication provided in the movable body for communicating with the constant pressure chamber of the variable pressure chamber and the third passage in accordance with an input from the input member, Provided on the front side of the movable body with the valve device that controls the shutoff A front coil provided with an output member and a return spring in the main body for urging the movable body to the rear side, the return spring being provided between the front pressure receiving portion and the front side of the main body. In a tandem booster composed of a spring and a rear coil spring provided between a rear pressure receiving portion and a partition wall, at least one of the pressure receiving portions is a plate fitted to the outer periphery of the hub portion, and this plate. The inner peripheral portion of the plate, while supporting the inner peripheral bead portion of the diaphragm, enters the groove on the outer periphery of the hub portion, and at least a part of the inner peripheral portion of the plate is formed. In contact with the front side wall surface of the groove, the supporting points at the ends of each coil spring are located radially outside the outer periphery of the hub portion, and the inner peripheral portion of the plate contacts the outer periphery of the hub portion. A position of the plate in contact with the front side wall surface of the groove is between the guide shoulder and the support point at the end of the coil spring when viewed in the axial direction of the hub. The plate is a tandem booster including a recess for receiving an end of the coil spring. 2. The front pressure receiving portion and the partition wall have recesses that overlap each other when viewed in the radial direction, and the ends of the coil springs are inserted into and supported by the recesses, respectively. Tandem booster.