JPS59227554A - Gap adjusting method of brake booster - Google Patents

Abstract

PURPOSE:To adjust the gap optimally by energizing a reaction disc with predetermined pressing force and inflating then adjusting the gap against a valve plunger with reference to the end face of inflated reaction disc. CONSTITUTION:Adhesives 30 is filled between two members 25, 26 of a valve plunger 11. Under such state where a gate valve 40 is opened to feed negative pressure into the path, a valve mechanism 7 is exchanged by means of a pressurizing system 36. Consequently, the atmosphere is led to the path 14 to vary the pressure. The pressure variation is detected by a detector 41 to stop advance of an input shaft 21 by means of the pressurizing system 36. Thereafter, a reaction disc 22 is pressed with predetermined pressing force by means of the other pressurizing system 37. The disc 22 will deform resiliently such that the right end face will inflate to the valve plunger 11 side and contact against the member 26 of the valve plunger 11. Upon stoppage of inflation and hardening of adhesives 30, both systems 36, 37 are released to complete the gap adjusting work.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake booster, and more particularly to an improvement in a reaction force transmission mechanism for transmitting brake reaction force.

Generally, when a brake booster is activated, the brake reaction force applied to the output shaft is transmitted from the output shaft to the input shaft via a reaction disk and a valve plunger that constitutes a valve mechanism. In this type of reaction force transmission mechanism, it is necessary to form a predetermined gap between the reaction disk and the valve plunger in order to determine the timing for starting reaction force transmission at the initial stage of operation of the brake booster. If the gap needs to be within a predetermined range with high precision, a gap adjustment mechanism that can adjust the gap between the two is provided, and this gap adjustment mechanism is adjusted to adjust the gap to the predetermined gap with high precision. is being carried out.

However, this type of conventional gap adjustment method does not take into account the variation in the amount of elastic deformation caused by variations in hardness, axial thickness, etc. of each reaction disk, and therefore -F Even if the gap is adjusted to the specified gap, if there is variation in the amount of elastic deformation of the reaction disk, there will eventually be variation in the timing at which the reaction force transmission starts, making it impossible to make a perfect adjustment. There wasn't.

In view of these circumstances, the present invention urges the reaction disk with a predetermined pressing force, elastically deforms it in advance to bulge toward the valve plunger side, and also deforms the end face of the bulged reaction disk. As a reference, the gap is adjusted by the gap adjustment mechanism so that, for example, the tip end face of the valve plunger comes into contact with the end face of the gap adjustment mechanism, and by such adjustment, the predetermined compression is applied to the reaction disk. When a force is applied, the reaction disc and valve plunger always come into contact and transmit the reaction force, so even if there is variation in the amount of elastic deformation for each reaction disc, the gap can always be adjusted optimally. It is designed so that it can be carried out.

The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, the interior of the shell 1 is formed by a power piston 2 and a tire flammable 3 stretched over the back surface of the power piston 2, forming a constant pressure chamber 4 at the front and a variable pressure chamber 5 at the rear. It is divided into
- A valve mechanism 7 for switching the fluid circuit is housed in a valve body 6 integrally provided on the shaft portion of the power piston 2.

The power piston 2, valve body 6, etc. are normally held in the non-operating position shown in the figure by a return spring 8.

The valve mechanism 7 has a first jr seat IO provided in the valve body 6.
, a second valve seat 12 formed on the valve plunger 11, and a valve body 13 seated on both valve seats 10.12. The outer peripheral portion of the first valve seat 10 communicates with the constant pressure chamber 4 through a passage 14 formed in the valve body 6, and the intermediate portion between the first valve seat 10 and the second valve seat 12 is connected to the valve body 6. It communicates with the variable pressure chamber 5 through a passage 15 formed in the body 6, and the inner peripheral portion of the second valve seat 12 (-1) communicates with the atmosphere through an air filter 16.

-1- The valve plunger 11 is prevented from being pulled out from the valve body 6 by a key member 20, and is connected to an input shaft 21 that is linked to a brake pedal (not shown), and the tip surface of the valve plunger 11 has a reaction One end surface of the reaction disk 22 faces the valve body 6 with a required gap δ, and the other end surface of the reaction disk 22 faces the valve body 6.
The output shaft 23 is opposed to the base end surface of the output shaft 23 which is slidably fitted into the output shaft 23 .

The key member 20 that prevents the valve plunger 11 from being pulled out from the valve body 6 is provided on the valve body 6 so as to be displaceable in the axial direction, and is curved and protrudes toward the variable pressure chamber 5, and is in the non-operating state shown in the figure. Then, the valve plunger 11 comes into contact with the inner surface of the shell L and restricts the free movement of the valve plunger 11 to the right with respect to the valve body 6, and when the brake pedal is depressed, the input shaft 21
Also, when the valve plunger 11 is actuated, the valve mechanism 7 can immediately switch the fluid circuit.

A brake booster having such a configuration is basically well known in the art, and its operation is no different from that of the conventional one, so a description of its operation will be omitted.

However, in this embodiment, the two-way valve plunger 11 is provided with a gap adjustment mechanism 24 that adjusts the gap δ between its tip surface and the reaction disk 22. This gap adjustment mechanism 24 consists of two members 2 that constitute the main body of the valve plunger 11.
5.26, a four part 27 is formed at the tip of one member 25 connected to the input shaft 21, and the other member 26 facing the reaction disk 22 is slidably fitted into the recess 27 of the other member 26. A convex portion 28 is formed, and an annular groove 29 is further formed at a predetermined position on the outer periphery of the convex portion 28. Then, adhesive 3 is applied between the four parts 27 and the convex parts 28.
0, and both members 25 are filled with this adhesive 30.
．． 26 are connected together. therefore,
The gap δ can be adjusted by adjusting the position where the two members 25 and 26 are connected by the adhesive 30.

FIG. 2 is a partial cross-sectional system diagram illustrating a method for adjusting the gap, in which the valve body 6 is fixed to a base 35, and the input shaft 21 and output shaft 23 have separate shafts 21 and 23, respectively. Pressurizing devices 36 and 37 that apply pressing force are interlocked. Then, the opening on the constant pressure chamber 4 side of the passage 14 formed in the valve body 6 is closed by a closing member 38, and one end of a conduit 39 is connected to this closing member 38, and the other end of this conduit is connected to an on-off valve 40. It is communicated with a negative pressure source (not shown) through it.

- The conduit 38 is provided with a pressure detector 41 that detects the pressure between the closing member 38 and the on-off valve 40, and a detection signal from this detector 41 is sent via the amplifier 42 to the pressurizing device. 36 can be input.

In the configuration described above, first, liquid or paste I adhesive 30 is filled between the two members 25 and 26 constituting the valve plunger 11, and both members 25 and 26 are kept in an extended state. We can assemble all the parts necessary for valve body 6. Next, with the on-off valve 40 opened to introduce negative pressure into the passage 14, the input shaft 21 is gradually advanced by the pressurizing device 36, and the fluid circuit by the valve mechanism 7 is switched. When the fluid circuit is switched by this valve mechanism 7 and atmospheric air is introduced into the passage 14 communicating with the constant pressure chamber 4 via the filter 1B, the pressure inside the passage 14 fluctuates. The pressure device 36 detects the pressure fluctuation by the detector 41, immediately stops the forward movement of the input shaft 21 +f-, and holds it at that position.

Next, the other pressurizing device 37 gradually pushes the output shaft 23 to the right in FIG. 2 until a predetermined pressing force is reached.

At this time, the reaction disk 22 is elastically deformed under the biasing force of the output shaft 23, and its right end surface is connected to the valve plunger 11.
I11 is extended to the side, and the output shaft 23 comes into contact with the left end surface of the valve plunger 11 before being biased with a predetermined pressing force. When the reaction disk 22 comes into contact with the valve plunger 11, the member 26 constituting the valve plunger 11 pushes out the adhesive 30 from inside the four parts 27 against the member 25 fixed by the input shaft 21.
Due to the elastic deformation of the action disk 22, the second
Move to the right in the diagram. Then, when the urging force of the output shaft 23 becomes a predetermined pressing force and the reaction disk 22 stops expanding due to elastic deformation, the member 26 also stops moving to the right.

In this state, wait until the adhesive 30 hardens, and when the adhesive 30 hardens, release the biasing force of the pressure devices 36 and 37, remove the closing member 38, and remove the valve body 6 from the base. Once removed, the gap adjustment work will be completed.

Note that the adhesive 30 extruded from the four parts 27 is captured by the annular groove 29 and does not leak to the outside of the valve plunger 11.

As can be understood from the above description, the gap between the valve plunger 11 and the reaction disk 22 is formed when the pressing force by the other pressing device 37 is released while the pressing force by the pressing device 36 is maintained. Since δ corresponds to the gap that can transmit the reaction force to the input shaft 21 at the moment when the brake reaction force applied to the output shaft 23 reaches the above-mentioned predetermined pressing force, δ corresponds to the gap that allows the reaction force to be transmitted to the input shaft 21. Even if there are variations in the amount of deformation, etc., it is possible to reliably adjust the waiting period for starting transmission of the reaction force to a predetermined time.

Note that when curing the adhesive 30, the curing may be accelerated by high frequency heating or the like, and any type of adhesive may be used; You need to choose something that will last. Furthermore, especially when using a liquid adhesive with low viscosity, the above-mentioned adjustment work may be performed with the valve body 6 facing vertically, that is, with the adhesive not flowing out from inside the four parts 27. good. Furthermore, in the embodiment described above, it is detected that the valve body 13 and valve seat 12 of the valve mechanism 7 open due to pressure fluctuations in the negative pressure, but it is also possible to use positive pressure instead of negative pressure. Of course.

Further, as shown in FIG. 3, approximately, the valve seat 12 of the valve plunger 11 and the valve seat 10 of the valve body 6 are held on the same plane with a jig 45 having a flat left end surface. In this state, the output shaft 23 is urged by the pressure device 37 to -1
- The adjustment work described above may also be performed. Above jig 4
The left end surface of the valve body 6 may have a step or a spherical surface for slightly displacing the valve seat 12 of the valve plunger 11 and the valve seat 10 of the valve body 6 in the axial direction, if necessary.

Furthermore, the gap adjustment mechanism 24 is not limited to the one described in the embodiment described above, and any conventionally known appropriate mechanism can be applied. For example, a gap adjustment mechanism can be used in which the two members 25 and 260 are screwed together and the gap δ is adjusted by changing the screwing position. In that case, a predetermined pressing force is applied to the output shaft 23 in advance. In addition, by changing the screwing position in this state, fluctuations in the pressing force acting on the output shaft 23 can be detected, and from this fluctuation it is possible to detect whether the valve plunger 11 and the reaction disk 22 are in contact. Although it depends on the configuration of the gap adjustment mechanism, it is not always necessary to bring the valve plunger 11 and the reaction disk 22 into contact with each other, and the adjustment may be completed when the valve plunger 11 and the reaction disk 22 are just about to come into contact. Even in this case, it is possible to perform adjustment with higher precision than in the past.

As described above, the present invention urges the reaction disk with a predetermined pressing force to bulge toward the distal end surface of the valve plunger, and the gap adjustment mechanism adjusts the gap based on the bulged end surface of the reaction disk. Since the adjustment is made, it is possible to perform the optimum gap adjustment even if there is variation in the amount of elastic deformation of the reaction disk.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
FIG. 3 is a partial cross-sectional system diagram illustrating a gap adjustment method using the gap adjustment mechanism shown in the figure, and FIG. 3 is a sectional view of essential parts showing another embodiment of the present invention. 11... Valve plunger 21... Input shaft 22.
・Reaction disk 23 ・Output shaft 24 ・・
・Gap adjustment mechanism 3B, 37...pressure device 45・
...Jig δ...Gap 2

Claims (1)

[Claims] A valve plunger that is linked to the input shaft, a reaction disk that faces the distal end surface of the valve plunger with a gap and at the same time faces the base end surface of the output shaft, and adjusts the gap between this reaction disk and the distal end surface of the valve plunger. and a gap adjustment mechanism that adjusts the gap adjustment mechanism to set the gap between the valve plunger and the reaction disk to a predetermined gap when the brake booster is not operating. In the adjustment method, the reaction disk is urged with a predetermined pressing force to bulge out toward the distal end surface of the valve plunger, and the gap is adjusted by the gap adjustment mechanism using the bulged end surface of the reaction disk as a reference. A method for adjusting a gap in a brake booster, characterized in that: