JP2904235B2 - Booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a booster, and more particularly, to an improvement in a reaction transmitting mechanism of a booster.

2. Description of the Related Art Conventionally, as a booster, a valve body slidably provided in a shell, a valve plunger slidably fitted to the valve body and interlocking with an input shaft, and An output shaft having a base fitted slidably and having the base opposed to the distal end surface of the valve plunger; and a distal end of the valve plunger interposed between the base of the output shaft and an end surface of the valve body. A reaction disc that transmits a reaction force of the output acting on the output shaft to the input shaft through the valve plunger, and the reaction disc and the valve plunger in a non-operating state where the input shaft is not advanced. It is known that a gap is formed between them (JP-A-54-111061, JP-B-2-38425). In the above-described booster, when the booster in which the input shaft is advanced is operated, the reaction disk is compressed in the axial direction, so that the shaft portion of the reaction disk bulges toward the distal end surface of the valve plunger. Thus, the reaction disc and the valve plunger come into contact with each other, whereby an output of a predetermined servo ratio is obtained from the output shaft. When the valve plunger and the reaction disk come into contact with each other, the output sharply increases, and the sharp increase in output is generally called jumping.

By the way, in the booster disclosed in Japanese Patent Publication No. 2-38425, the hardness of the rubber used for the reaction disk is increased, so that the brake pedal is depressed and the brake pedal is released. The hysteresis, which is the difference between the input signals, is increased, thereby giving the driver a good brake feeling. However, when the rubber hardness of the reaction disk is increased in order to secure a large hysteresis, the hardness of the reaction disk becomes higher than that at normal temperature when the booster is used at a low temperature.
For this reason, the amount of jumping at low temperatures becomes larger than that at normal temperatures, which causes a disadvantage that the driver's brake feeling is hindered. In addition,
A structure in which a metal annular member is embedded in a reaction disk is also known (for example, Japanese Utility Model Publication No.
No. 9975). According to the reaction disk disclosed in Japanese Utility Model Publication No. 59-9975, resistance can be applied to the elastic deformation of the reaction disk by the annular member, so that the hysteresis is substantially increased without increasing the hardness of the reaction disk. It is possible to However, such a configuration has the following problems. That is, in the reaction disk disclosed in Japanese Utility Model Publication No. 59-9975,
Since the entire annular member is buried in the reaction disk, the embedded position of the annular member varies when the reaction disk is manufactured. In addition, when the reaction disk is compressed and elastically deformed after the assembly is completed, the annular member is displaced in the reaction disk in the radial direction, so that there is a disadvantage that the hysteresis varies.

SUMMARY OF THE INVENTION In view of the above, the present invention provides a valve body slidably provided in a shell,
A valve plunger slidably fitted to the valve body and interlocking with the input shaft; and an output having a base slidably fitted to the valve body and having the base opposed to a distal end surface of the valve plunger. The shaft is interposed between the base of the output shaft and the end face of the valve body, and is opposed to the tip face of the valve plunger to transmit the reaction force of the output acting on the output shaft to the input shaft via the valve plunger. A booster in which a gap is formed between the reaction disc and the valve plunger in a non-operation state in which the input shaft is not advanced, wherein the reaction disc has an annular shape having a higher hardness than the reaction disc. A valve body that embeds the member to expose a part of the peripheral surface of the annular member and abuts the reaction disc; Forming a stepped portion on the end face, the stepped portion of the valve body is engaged with the peripheral surface of the annular member which is exposed above, it is obtained by blocking the radial displacement of the annular member.
The present invention also provides a valve body slidably provided in a shell, a valve plunger slidably fitted to the valve body and interlocking with an input shaft, and a base slidably mounted on the valve body. While fitting, the output shaft whose base is opposed to the distal end surface of the valve plunger, is interposed between the base of the output shaft and the end surface of the valve body and faces the distal end surface of the valve plunger, A reaction disc that transmits a reaction force of the output acting on the output shaft to the input shaft via the valve plunger, and a gap is formed between the reaction disc and the valve plunger in a non-operating state where the input shaft is not advanced. In the booster, an annular member having a higher hardness than the reaction disk is embedded in the reaction disk to expose a part of a peripheral surface of the annular member. At the same time, a step is formed at the base of the output shaft in contact with the reaction disk, and the step of the output shaft is engaged with the exposed peripheral surface of the annular member, thereby preventing radial displacement of the annular member. Things.

According to this structure, when the reaction disk is compressed in the axial direction during operation of the booster, the reaction disk is elastically deformed not only in the axial direction but also in the radial direction. Will be done. At that time, the annular member can apply resistance to the radial elastic deformation of the reaction disk.
On the other hand, when the input shaft is switched from the operating state to the non-operating state in which the input shaft is retracted, since the restoring force of the reaction disk is increased by the annular member, the reaction disk returns to the original state before elastic deformation. You can return quickly. Therefore, large hysteresis can be secured without increasing the hardness of the reaction disk. Furthermore, since a part of the peripheral surface of the annular member embedded in the reaction disc is exposed,
When manufacturing the reaction disk, the exposed portion of the annular member can be used as a positioning portion. Therefore, there is no variation in the embedded position of the annular member in the reaction disk. Further, since the exposed peripheral surface of the annular member is, for example, supported by a step portion of the valve body and cannot move in the radial direction, when the reaction disk is compressed and elastically deformed, the annular member reacts. It is possible to prevent the disk from moving in the radial direction in the disk. Therefore, it is possible to reduce the variation in the hysteresis for each reaction disk.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows a main part in a shell of a negative pressure type brake booster. In FIG. 1, reference numeral 1 denotes a valve body slidably provided in a shell (not shown), and a shaft portion of the valve body 1 is provided with a stepped hole 1A.
A valve plunger 2 constituting a valve mechanism is slidably fitted in the small-diameter portion 1a on the right side of the stepped hole 1A, and an input shaft (not shown) is connected to the right end of the valve plunger 2. ing. The step portion of the stepped hole 1A in the valve body 1 is a cylindrical portion 1b extending toward the left side,
A concave portion 3a formed at the base of the output shaft 3 in the cylindrical portion 1b.
Is slidably fitted. Also, the concave portion 3 of the output shaft 3
A disk-shaped reaction disk 4 made of rubber is accommodated in a, and the outer peripheral side of a right end surface 4a of the reaction disk 4 is brought into contact with the distal end surface of the cylindrical portion 1b of the valve body 1. I have to. The left end face 4 b of the reaction disk 4 is in contact with the bottom of the recess 3 a of the output shaft 3. As described above, the reaction disk 4 is sandwiched between the bottom of the concave portion 3a of the output shaft 3 and the distal end surface of the cylindrical portion 1b, and at the same time, the shaft of the right end surface 4a of the reaction disk 4 is It faces the tip surface 2a of the plunger 2. In the non-operation state of the brake booster shown in FIG.
A required gap is formed between the right end face 4a of the reaction disk 4 and the tip end face 2a of the valve plunger 2. The above-described configuration and the operation based thereon are no different from those of the conventionally known negative pressure type brake booster. When the brake pedal is depressed from the non-operating state shown in the drawing and the input shaft is advanced, the reaction disk 4 is moved. Becomes compressed in the axial direction. The compressed reaction disk 4 has the shaft portion of the right end surface 4a bulging toward the distal end surface 2a of the valve plunger 2, so that the gap is eliminated and the right end surface 4a of the reaction disk 4 is removed.
a comes into contact with the distal end surface 2 a of the valve plunger 2. In this case, an output having a predetermined servo ratio can be obtained from the output shaft 3. At the same time, an output reaction force acting on the output shaft 3 is transmitted to an input shaft (not shown) via the reaction disk 4 and the valve plunger 2. When the reaction disc 4 and the valve plunger 2 come into contact with each other, the output sharply increases, and the sharp increase in the output is generally called jumping. In this embodiment, the annular member 5 having a higher hardness than the reaction disk 4 is embedded in the right end face 4a of the reaction disk 4. That is, in FIG. 1, the right end face 4a of the reaction disc 4
The metal annular member 5 is embedded integrally with the valve plunger 2 so as to have the same axis. The outer diameter of the annular member 5 is set to be larger than the outer diameter of the distal end of the valve plunger 2. The right end of the annular member 5 has a reaction disk 4 on the outer peripheral side of the annular member 5.
And the right side inner peripheral surface of the annular member 5 is exposed to a predetermined dimension in the axial direction. An annular projection 1c provided on the inner peripheral edge of the distal end surface of the cylindrical portion 1b is fitted to the exposed right inner peripheral surface of the annular member 5. As a result, the annular member 5 is supported by the annular protrusion 1c of the valve body 1, so that the annular member 5 cannot move in the radial direction. The cylindrical portion 1b
Is in contact with the right end surface 4a of the reaction disk 4 on the outer peripheral side of the annular member 5, and at the same time, the distal end surface of the annular projection 1c is on the right side of the reaction disk 4 on the inner peripheral side of the annular member 5. It is in contact with the end face 4a. In this state, the right end face 4a of the reaction disk 4 on the inner peripheral side of the annular member 5 and the valve plunger 2
A required gap is maintained between the front end surface 2a and the front end surface 2a. Furthermore, the left end of the annular member 5 is located at the axial center of the reaction disk 4, and therefore does not hinder the elastic deformation of the reaction disk 4 in the axial direction. The left side portion of the disk 4 can be elastically deformed without hindrance. According to the present embodiment having such a configuration, when the brake booster is operated and the reaction disk 4 is compressed in the axial direction, the reaction disk 4 is elastically deformed inward in the radial direction. At that time,
The annular member 5 applies resistance to the elastic deformation of the reaction disk 4 in the radial direction. Therefore, the reaction disk 4 on the inner peripheral side of the annular member 5
The right end surface 4a of the swelling is in contact with the valve plunger 2 while swelling while applying resistance to elastic deformation. On the other hand, when the operating state is switched to the non-operating state in which the input shaft is retracted, the restoring force is increased by the annular member 5 embedded in the reaction disc 4,
The reaction disk 4 quickly returns to the original non-operation state. Therefore, in the present embodiment, it is possible to increase the hysteresis without increasing the hardness of the reaction disk 4, thereby increasing
A good brake feeling can be given to the driver. Further, since the hardness of the rubber of the reaction disk 4 is not increased, the jumping amount at a low temperature does not become extremely large as compared with the jumping amount at a normal temperature. Further, since the inner peripheral portion on the right side of the annular member 5 embedded in the reaction disk 4 is exposed, the inner peripheral portion on the right side of the annular member 5 is Annular member 5 in disk 4
It can be used as a positioning part. for that reason,
According to this embodiment, there is no variation in the embedment position of the annular member 5 as compared with the conventional one in which the annular member 5 is completely buried in the reaction disk 4. Further, the inner peripheral portion on the right side of the exposed annular member 5 is:
Since the annular projection 1c of the valve body 1 is supported so as not to move in the radial direction, the annular member 5 is prevented from moving inside the reaction disk 4 in the radial direction when the reaction disk 4 is compressed and deformed. be able to. Therefore, variation in hysteresis for each reaction disk 4 can be reduced. (Second Embodiment) FIG. 2 shows a second embodiment of the present invention. In this second embodiment, after the annular member 105 is embedded in the right end surface 104a of the reaction disk 104, Contrary to the first embodiment, the annular member 1
The right end surface 104a of the reaction disk 4 located on the outer peripheral side of the annular member 105 is continuously notched in the circumferential direction so that the outer peripheral portion on the right side of the annular member 105 is exposed. The outer peripheral portion on the right side of the annular member 105 is fitted into a circular notch 101d provided on the inner peripheral edge of the cylindrical portion 101b of the valve body 101. In this state, the right end surface 104a of the reaction disk 104 located inside and outside the annular member 105 is in contact with the front end surface of the cylindrical portion 101b and the bottom of the notch 101d, and the right end surface 104a and the valve plunger 102 Tip surface 102a
And a gap is maintained between them. Other configurations are the same as those of the first embodiment, and even with the configuration of the second embodiment, the same operation and effect as those of the first embodiment can be obtained. (Third Embodiment) FIG. 3 shows a third embodiment of the present invention. In the third embodiment, the annular member 205 is replaced with the first embodiment shown in FIG. The reaction disk 204 is embedded in the left end surface 204b. In the third embodiment, the output shaft 203
A circular projection 203b bulging rightward is formed at the bottom of the recess 203a in FIG.
b is fitted to the left inner peripheral portion of the exposed annular member 205. In the third embodiment, the annular member 2
05 is located at the axial center of the reaction disk 204. Further, the right end surface 204a of the reaction disk 204 is a flat surface, and the distal end surface of the tubular portion 201b of the valve body 201 that is in contact with the right end surface 204a is also a flat surface. The other configuration is the same as that of the second embodiment. Even with the configuration of the third embodiment, the same operation and effect as those of the first embodiment can be obtained. (Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention. In the fourth embodiment, the unevenness of the concave portion 203a of the output shaft 203 in the third embodiment and the reaction This is the reverse of the unevenness of the left end surface 204b of the disk 204. That is, the left end surface 304b of the reaction disk 304
5 is integrally buried, and a left end surface 304a of the reaction disk 304 on the outer peripheral side of the annular member 305 is continuously cut in the circumferential direction to expose the left outer peripheral portion of the annular member 305. Then, the concave portion 3 of the output shaft 303
The bottom of 03a is provided with a circular recess 303c,
The left outer peripheral portion of the annular member 305 is fitted into the concave portion 303c. Other configurations are described in the third section above.
This is the same as the embodiment, and even with such a configuration of the fourth embodiment, the same operation and effect as those of the first embodiment can be obtained. The material of the annular members 5, 105, 205, and 305 may be a material having higher hardness than the reaction disk, and may be a synthetic resin or a hard rubber.

As described above, according to the present invention, there is obtained an effect that a large hysteresis can be secured without increasing the hardness of the reaction disk. Further, an effect is obtained that variation in hysteresis for each reaction disk can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 valve body 1c annular projection (step) 2 valve plunger 3 output shaft 4 reaction disk 5 annular member

Claims (2)

(57) [Claims] A valve body slidably provided in a shell, a valve plunger slidably fitted to the valve body and interlocking with an input shaft, and a base slidably fitted to the valve body. And an output shaft having the base opposed to the distal end surface of the valve plunger, and an output shaft interposed between the base of the output shaft and an end surface of the valve body and opposed to the distal end surface of the valve plunger. A reaction disc for transmitting the reaction force of the output acting on the shaft to the input shaft via the valve plunger, wherein a double space is formed between the reaction disc and the valve plunger when the input shaft is not advanced. In the force device, an annular member having a higher hardness than the reaction disk is embedded in the reaction disk, and a part of a peripheral surface of the annular member is exposed. In both cases, a step is formed on the end face of the valve body that comes into contact with the reaction disk, and the step of the valve body is engaged with the exposed peripheral surface of the annular member, thereby preventing radial displacement of the annular member. A booster characterized by the following. 2. A valve body slidably provided in a shell, a valve plunger slidably fitted on the valve body and interlocking with an input shaft, and a base slidably fitted on the valve body. And an output shaft having the base opposed to the distal end surface of the valve plunger, and an output shaft interposed between the base of the output shaft and an end surface of the valve body and opposed to the distal end surface of the valve plunger. A reaction disc for transmitting the reaction force of the output acting on the shaft to the input shaft via the valve plunger, wherein a double space is formed between the reaction disc and the valve plunger when the input shaft is not advanced. In the force device, an annular member having a higher hardness than the reaction disk is embedded in the reaction disk, and a part of a peripheral surface of the annular member is exposed. In both cases, a step is formed at the base of the output shaft in contact with the reaction disk, and the step of the output shaft is engaged with the exposed peripheral surface of the annular member, thereby preventing radial displacement of the annular member. A booster characterized by the above-mentioned.