JPS58202146A - Booster for brake - Google Patents

Abstract

PURPOSE:To stabilize the characteristics of the booster even though the manufacturing accuracies of each members are reduced by a method wherein a gap adjusting mechanism, adjusting the gap between a reaction disc and a valve plunger, is provided in the brake booster. CONSTITUTION:An adjusting nut 26, constituting the gap adjusting mechanism 25 adjusting the gap 8 between a valve plunger 11 and a reaction disc 21, is screwed to the engaging hole 3c of a valve body 3. A disc spring 27 is mounted between the nut 26 and the larger diametral part 22a of an output shaft 22 elastically. The output shaft 22 is penetrated through the hole 26a of the nut 26 loosely and the engaging part 22b is engaged with the hole 26a so that the nut 26 can not be rotated with respect to the output shaft relatively. When the output shaft 22 is rotated under this condition, the nut 26 is also rotated and said gap 8 may be adjusted through the disc spring 27.

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, a brake reaction force applied to an output shaft is transmitted from the output shaft to the input shaft via a rear aximine 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, but in the past, each part was manufactured with high precision in order to keep the gap within a predetermined range. It was impossible to adjust the gaps after each part was manufactured. As a result, conventionally, especially when it is necessary to strictly control the allowable range of the gap, after manufacturing each part, the dimensions of those parts are measured and parts whose gap falls within a predetermined range are selected and then assembled. This required a great deal of effort.

In view of these circumstances, the present invention provides a brake booster with a gap adjustment mechanism that adjusts the gap between the reaction disc and the valve plunger, thereby making it extremely easy to manufacture each part with high accuracy. The present invention provides a brake booster capable of obtaining a predetermined tEIJ gap size.

The present invention will be explained below with reference to the illustrated embodiments. In Fig. 1, (1) is a front shell, (2) is a beam shell, (3) is a valve body, and (4) is this valve body (
A power piston integrally formed with the power piston (3) engages the inner circumference (6a) of the diaphragm (6) in the engagement groove (5) formed on the back surface of the power piston (4), and also engages the inner circumference (6a) of the diaphragm (6) (1) The outer periphery (6b) of the diaphragm (6) is sandwiched between the palm shell (2) and the inside is divided into a negative chamber (7) and an atmospheric pressure chamber (8).

The terminal cylinder part (3a) of the valve body (3) protrudes from the opening (2a) of the palm shell (2) to the outside while keeping airtight with a sealing member (9), and the valve body (3a) has a valve inside. A mechanism (lO) is provided. This valve mechanism (10) is equipped with a valve plunger (II) and an input shaft (12) as well as conventionally known ones, and when in the non-operating state, the 9-pressure introduction pipe (13) of the front shell (1) is used. Pressure chamber (
7) The zero pressure that is constantly introduced into the valve body (3)
), the gap between the valve element (15) and the valve seat (3b) of the valve body (3), and the radial passage (16) into the atmospheric pressure chamber (8). is introduced into the valve body (3) by the return spring (17).
), the power piston (4), etc., are held in a non-operating position.

A key member (20) that prevents the valve plunger (11) from being pulled out of the valve body (3) is
3) A bifurcated engaging portion (20a) at the tip of the insert.
is engaged with the intermediate small diameter portion of the valve plunger (II), and this key member (20) is engaged with the diaphragm (6).
The inner circumferential portion (6a) of the valve body (3) prevents it from falling off from the valve body (3). And the valve plunger (II
) is opposed to one end surface of the reaction disk 121) fitted into the retaining hole (3c) of the valve body (3) with a required distance of ffl+6), and the other end surface of the reaction disk 215 is the above engagement hole (3C
) of the output shaft (22) which is slidably fitted into the large diameter end (
The tip of this output shaft (22) 1□, which is in contact with 22a), slidably passes through the seal member (23) fitted into the four recessed openings a) of the front shell (1). It is linked to a piston of a master cylinder (not shown).

Therefore, an adjustment nut (26) constituting an adjustment mechanism (25) for adjusting the distance (6) is screwed into the engagement hole (3C) of the valve body (3) at its opening side position. death,
This nut (26) and the large diameter part (22a) of the output shaft (22)
) is loaded with a countersunk (27). Output shaft (2
2) 8 parts of holes (26a)
), and a non-circular (polygonal, two-sided chamfered, half-moon shape, etc.) engaging portion (22b) is formed in the penetrating portion, and the hole (26a) of the nut (26) also has a shape corresponding to the cross-sectional shape of the engaging portion (22b),
Since the above structure prevents the two from rotating relative to each other, if the output shaft (22) is rotated and the nut (26) is rotated integrally with the output shaft (22), the Ill spring (27) is rotated. By adjusting the force applied to the right side of the output shaft (22), the elastic deformation of the reaction disk (21) can be adjusted and the reaction disk (21) and valve plunger C can be adjusted. 8 with eyes)
The gap (δ) can be adjusted. This gap (5) is
In order to eliminate dimensional errors, the valve body (15) must be aligned with the valve seat (3b).
) It is desirable to adjust the brake booster to a predetermined value when the brake booster is seated in the operating state. Tighten the adjustment nut (26) so that the gap @(6) becomes a predetermined value, taking into consideration the actual gap between the screw and the screw. Note that when adjusting the amount of rotation of the nut (26) during assembly of the brake booster, it is not necessary to connect the output shaft (22) and the nut (26) to their retaining portion (22b) and hole (26a). It is not necessary to connect them so that they cannot rotate relative to each other.

On the other hand, when the above-mentioned gap (5) can be adjusted by rotating the output shaft (22) from the outside after the brake booster is assembled, as in this embodiment, a more complete brake booster negative pressure can be introduced for operation. When the output of the output shaft (22) reaches a certain value, the resulting reaction force causes the reaction disc (22) to
1 deforms and contacts the valve plunger (11), thereby transmitting a reaction force to the input shaft (12). The magnitude of the reaction force transmitted to the input shaft at that moment is between the above range @(
δ), so the amount of adjustment rotation of the output shaft (22) and adjustment nut (26) can be calculated from the difference between the magnitude of the reaction force and the magnitude of the base reaction force.
The reaction force can be matched directly with the reference A. According to this adjustment method, even if there are variations in the elasticity of the reaction disc (21), variations in the axial dimension of the valve body, and variations in the overall length of the plunger, it is possible to obtain the above-mentioned standard reaction force with all brake boosters. There is an advantage.

It should be noted that the operation of the brake booster itself is the same as that of conventionally known devices, so a description thereof will be omitted. Also, the above ■■ spring (27) is connected to the valve plunger (11) during sudden braking.
) to ensure a large flow area between the atmosphere and the atmospheric pressure chamber (10) in the valve mechanism (lO), and is not necessarily necessary. The #adjustment nut (26) and the large diameter portion 12a) of the output shaft (22) may be brought into direct contact with each other. The dish splashes again (27
) may of course be replaced with an elastic body such as rubber.

2 and 3 are modified examples based on the embodiment shown in FIG. 1, respectively, and in the embodiment shown in FIGS. (30
) is not screwed into the engagement hole (3C) of the valve body (3) but to the outer periphery of the protrusion (3d) concentric with the engagement hole (3C), and the adjustment nut (30) and the large diameter section (22) of the output shaft (22) are screwed together.
A disc spring (31) is loaded between the

This plate spring (31) is connected to the engaging portion (2) of the output shaft (22).
2b) to rotate integrally with the engagement hole (
3ta), and a protrusion (31b) is formed on its outer periphery to engage with a recess (not shown) in the adjustment nut (30) and rotate the adjustment nut (30) together. .

In addition, the gap adjuster 4IiI (34) shown in FIG.
) consists of a tip-shaped adjustment nut (32) separate from the
A sealing member (23) that slidably passes through the output shaft (22) is disposed within the concave portion 11a) of this knob-shaped adjustment nut (32), and the adjustment nut (32) is connected to the front shell ( 1) is screwed onto the output shaft (22) so as to move forward and backward automatically in the axial direction, and a spring (33) is loaded between this and the large diameter portion 122a) of the output shaft (22). Further, the adjustment nut (32) is formed with a slit 132a) that engages with a jig for rotating the adjustment nut (32). Note that the O-ring [23a] is a sealing member between the master cylinder (not shown) and the front shell (1).

Gap adjustment mechanisms (29) and (3) shown in Figures 2 and 3 above.
Also in 4), the deformation wrinkles of the reaction disk (21) can be adjusted by rotating the adjustment screws (30) and (32) directly or via the output shaft (22) and the countersunk (31). This is clear and thus allows adjustment of the gap between the reaction disc (21) and the valve plunger (11). In addition, as another example, the piston of the master cylinder is kept airtight and the front shell (1) is
An adjusting nut may be screwed onto the piston and displaceable in the axial direction, and a spring may be loaded between the adjusting nut and the output shaft.

Next, the gap adjustment mechanisms shown in Figures 8g1 to 3 above all compress and deform the reaction disk (21) to adjust the gap (6) between this and the valve plunger (11). The same objective can be achieved by adjusting the position of the tip of the valve plunger as shown in the figure, or by adjusting the position of the center of the reaction disk as shown in FIG.

First, in FIG. 4, in the gap adjustment mechanism (38) of this embodiment, the valve plunger (35) is connected between the member 135a) on the reaction disk (21) side and the member (35b) on the input shaft (36) side. It consists of two parts (35
a) and (35b) are screwed together. Valve plunger (
35) is made into two members, in this example, the key member (20) in the previous example is omitted, and the valve plunger (35) is removed using the small diameter ffa+3e) formed on the valve body (3). I'm trying to stop it. In this way, when the valve plunger (35) is made into two parts (35a) and (35b) and they are screwed together, by adjusting the threaded joints of both parts, the input to the valve body (3) can be made in the non-operating state. The shaft (36) side member (35b), that is, the valve body (15
) and the valve seat (3b), and therefore the gap between the valve plunger (35) and the reaction disk (21) at the time of starting the operation of the brake booster can be adjusted.

The amount of screw engagement between the two members (35a) and (35b) can be adjusted when assembling the brake booster;
An engagement notch (35C) is formed in the axial direction of the outer peripheral surface of the valve body (3), and the notch (35C) is formed in the valve body (3).
5c) is formed, and both +
By engaging the members (35C) and (3f), the member (3
Although 5al can be moved in the axial direction of the valve body (3), relative rotation is not possible. And in this state,
Other member 1 connected to this by an input shaft (36)
35b), a thin plate-like connecting member (37) made of spring steel or synthetic resin is inserted between the slits formed in each of the input shaft (36) and the member (35b) to provide elasticity. are doing. Further, since the end of the human power shaft (36) is connected to a brake pedal or a tester, the input shaft (36) is made into two members (36a) and (36b), and both are connected so as to be relatively rotatable.

Therefore, when the member (36a) of the input shaft (36) is rotated, the member (35b) of the valve plunger (35) connected to this input shaft (36) via the connecting member (37)
can be rotated together, and the gap between the valve plunger (35) and the reaction disk (21) can be adjusted as described above. The input shaft (36) swings relative to the member (35b) in accordance with the amount of depression of the brake pedal, but the connecting member (37) swings in the direction perpendicular to the plane of the paper in Fig. 4+8). Due to the inserted slit, the elasticity of the connecting member (37) allows the swinging along the plane of the paper, and the input shaft (36) works together.
) is allowed to swing in any direction.

In addition, as a modification to this embodiment, the valve plunger is constructed from a sail, and a screw hole is threaded through the shaft portion of the valve plunger.
The adjustment bolt screwed here may be used to directly adjust the gap between the tip surface of the blade and the reaction disk (21) by rotating the blade shaft 136a). In addition, in Fig. 4+8), the small diameter portion (3e) of the valve body is used to prevent the valve plunger (35) from being pulled out, but it is of course possible to use a conventionally known key member to prevent the valve plunger (35) from being pulled out. In this case, the same assembly method as the conventional method can be used.

Next, in the embodiment shown in Fig. 5+8) and Tb), the gap between the two can be adjusted by adjusting the position of the central part of the reaction disk (40) with respect to the valve plunger (If). It shows the mechanism (39). In this embodiment, the output shaft (41) has a large diameter portion (41a) and a rod portion (41
b), and the rod part (41b) is screwed into the large diameter part (41a) so that its end can protrude from the large diameter part (41a) toward the reaction disk (40). I have to. and reaction disc (
40) is also two members (40a) with separate shaft parts, (
40b), and the diameter of the shaft member (40a) is made to substantially match the diameter of the protruding end of the rod portion (41b).

Furthermore, a non-circular (polygonal, bidirectional, half-moon, etc.) engaging portion (41c) is provided on the front end surface of the large diameter portion (41a)
), and this engaging portion (41c) is attached to the valve body (3
) into the same-shaped Hoya hole (42a) of the retaining ring (42) fitted into the engaging hole (3C) of the rod part (
The large diameter portion (41a) is prevented from rotating when adjusting the gap by rotating the portion (41b). The above retaining ring (42)
has an elastic protrusion (42b) on its outer periphery, and is fixed in the retaining hole (42a) by the frictional force caused by the elasticity.

In the embodiment shown in FIG. 5, the reaction disk (40)
Although it is composed of two members, it goes without saying that it may be a single member. Further, it is desirable that the end portion of the rod portion (41b) is spherical. Furthermore, as a modification to this embodiment, the output shaft may be constructed integrally, and an adjustment bolt having a relatively large diameter head may be screwed into the large diameter shaft of the reaction disk (40). In addition, a pin fixed to the valve body (3) is engaged with a groove provided on the front surface or front surface of the large diameter portion to prevent rotation of the large diameter portion, or the end portion of the return spring (17) is used as the pin. You may.

As the present invention has been described based on the various embodiments described above, the present invention is provided with a gap adjustment mechanism for adjusting the gap between the beam action disk and the valve plunger, and therefore is different from the conventional one. It is possible to adjust the gap m which was impossible,
Therefore, it is possible to easily obtain a desired gap without manufacturing each member with extremely precise precision, and to stabilize the characteristics of each brake booster.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a first embodiment of the present invention, Fig. 2 fa) is a sectional view of main parts showing the second embodiment, Fig. 2 fb
) is a front view of the plate spring (31) in Fig. 2 f8), Fig. 3 is a sectional view of the main part showing the third embodiment, and Fig. 4 (a) is a front view of the countersunk spring (31) in Fig. 2 f8).
A cross-sectional view of the main part showing the embodiment, Fig. 4 ib) is shown in Fig. 4 f.
A) is a perspective view of the member (35a), FIG.
FIG. 3 is a perspective view of the output shaft (41) and retaining ring (42) of FIG. +1)...Front shell (2)...Rear shell (3)
)... Valve body (4)... Power piston (6
)...Diaphragm (10)・Valve mechanism (n), (3
5)・Valve plunger port 2), (36) input shaft (21), (40)・-'reaction disk (22)
), (41)...Output shaft (25), (29), (34), (38), (39)...
・Gap adjustment mechanism (6) Gap Figure 2 (a) Figure 2 (b) Figure 3

Claims (1)

[Claims] A valve body that houses a valve mechanism that controls the opening and closing of a pressure fluid flow path in response to forward and backward movement of the input shaft, a power piston provided in this valve body, and an end portion slidably fitted into the valve body. The blade shaft is provided with a reaction disk interposed between the end of the output shaft and the valve plunger constituting the valve mechanism, and the reaction force applied to the output shaft is transmitted through the reaction disk and the valve plunger. In the brake booster that transmits power to the input shaft,
A brake booster comprising a gap adjustment mechanism for adjusting the gap between the reaction disc and the valve plunger.