JP4822199B2 - Pneumatic booster - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pneumatic booster mounted on a braking device of a vehicle such as an automobile.
[0002]
[Prior art]
Conventionally, this type of pneumatic booster prevents the brake pedal from jumping into the passenger compartment by deforming the pneumatic booster in the event of a vehicle collision, etc. There is a pneumatic booster called a crushable booster that suppresses injury to the lower limbs, and is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-219126.
[0003]
In this publication, as shown in FIG. 5, a master cylinder mounting surface 102 of a shell 101 of a pneumatic booster 100 on which a master cylinder 104 is mounted by a bolt 108 is divided into an inner peripheral member 102a and an outer peripheral member 102b. The inner peripheral member 102a and the outer peripheral member 102b are fixed by a rivet 103 or the like.
[0004]
In the pneumatic booster 100, the master cylinder is disposed in the engine room of the vehicle, and the master cylinder 104 is pushed in the direction of the passenger compartment when the engine room is crushed due to a vehicle collision or the like. The fixing between the inner peripheral member 102a and the outer peripheral member 102b to which the 104 is attached is released by the breakage of the rivet 103, and the master cylinder 104 enters the shell 101, so that the output rod 105, the valve body 106, and the input rod The brake pedal (not shown) connected to the input rod 107 is prevented from being pushed out into the passenger compartment when 107 is pushed.
[0005]
[Problems to be solved by the invention]
However, although the conventional pneumatic booster sufficiently achieves the purpose as a crushable booster, when manufacturing, a plurality of inner peripheral members 102a and outer peripheral members 102b are formed by rivets 103 or the like. Since it is necessary to fix the parts, there is a problem that the assembly of the pneumatic booster becomes complicated and the number of parts increases.
[0006]
The present invention has been made in view of the above points, and an object thereof is to provide a pneumatic booster that can be easily assembled and can suppress an increase in the number of parts.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention of claim 1 defines a constant pressure chamber and a variable pressure chamber in a shell by a power piston, and introduces gas into the variable pressure chamber in response to an input to an input rod. Then, a thrust is generated in the power piston by the pressure difference generated between the constant pressure chamber and the variable pressure chamber, and the piston of the master cylinder attached to one side of the shell is operated through the output rod by the thrust of the power piston. In the pneumatic booster, the one surface side of the shell includes an annular outer peripheral member having an opening at a substantially center, and an inner portion on which the master cylinder is attached to cover the opening of the outer peripheral member. and a peripheral member, one of the inner peripheral member or the outer peripheral member comprises a plurality of members, the other members by fixing the members to each other of the plurality of Characterized by clamping the end.
[0008]
With the above configuration, the outer peripheral member and the inner peripheral member can be fixed without using a rivet or the like. Further, by fixing the plurality of members, the peripheral end portion of the other member can be clamped, and assembly processing for fixing the outer peripheral side member and the inner peripheral side member becomes easy.
[0011]
Further, the inventions of claim 2, in addition to the inventions of the claim 1, wherein the plurality of members are inner peripheral member, wherein the master cylinder and the plurality of inner peripheral member, the same bolt Are fixed to each other.
[0012]
With the above configuration, a plurality of inner peripheral side members and the master cylinder can be fastened together by bolts for attaching the master cylinder, thereby fixing the plurality of inner peripheral side members to each other without increasing the number of parts and the number of assembly steps. The outer peripheral side member and the inner peripheral side member can be fixed.
[0013]
Further, the inventions of claim 3, in addition to the inventions of the claim 2, the outer peripheral end portion of the inner peripheral member is predetermined inclination angle so as to have radially spread toward the master cylinder It is characterized by having.
[0014]
With the above configuration, alignment during assembly is facilitated, and by adjusting the inclination angle, an external force for releasing the fixation between the outer peripheral member and the inner peripheral member can be freely set.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
As shown in FIG. 1, the pneumatic booster 1 of the present embodiment is a tandem pneumatic booster, and the inside of the shell 2 is divided into two chambers, a front chamber 4 and a rear chamber 5, by a partition wall 3. It is partitioned. Power pistons 8 and 9 are movably mounted in the front chamber 4 and the rear chamber 5 through diaphragms 6 and 7, respectively. The first and second constant pressure chambers 4a and 5a and the first and second variable pressure chambers 4b and 5b are defined. The first and second constant pressure chambers 4a and 5a are in communication with each other via a passage 11, and the first and second variable pressure chambers 4b and 5b are in communication with each other through a passage 10.
[0017]
A valve body 12 is connected to the power pistons 8 and 9, and one end of the valve body 12 is inserted into the rear wall of the shell 2 in an airtight and slidable manner and extends to the outside. An output rod 14 is connected to the other end side of the valve body 12 via a reaction disk 13. A plunger 15 is provided in the valve body 12 so as to face the reaction disk 13 with a predetermined gap.
[0018]
One end of an input rod 17 is connected to the plunger 15, and the other end of the input rod 17 is slidably inserted into a breathable dust seal 16 attached to the end of the valve body 12 and extends to the outside. Has been issued. In the valve body 12, the communication between the first and second variable pressure chambers 4b and 5b and the outside (atmosphere) or the constant pressure chambers 4a and 5a is blocked or blocked according to the relative position between the plunger 15 and the valve body 12. A control valve 18 for switching is provided. A reaction force adjusting mechanism 19 having a compression spring 19 a set with a predetermined set load is provided at the distal end portion of the plunger 15.
[0019]
An opening 33 concentric with the valve body 12 is formed at the center of the front end portion 32 (outer peripheral member) which is the master cylinder mounting surface side (one surface side of the shell) of the shell 2. An inner peripheral edge portion 32a (circumferential end portion) of the front end portion 32 that defines the opening 33 is folded at a predetermined inclination angle toward the first constant pressure chamber 4a, and the inner peripheral edge portion 32a has a circumferential direction. An annular recess 32b for holding the O-ring 37 is provided.
[0020]
A front member 34 (inner peripheral side member) having substantially the same thickness as the shell 2 is attached to the opening 33 so as to cover the opening 33 from the outside of the pneumatic booster 1. The outer peripheral edge 34a is folded toward the outside of the pneumatic booster 1 with a predetermined inclination angle so that the outer peripheral edge 34a and the inner peripheral edge 32a overlap each other by a predetermined amount. In other words, the outer peripheral edge 34a of the front member 34 has a predetermined inclination angle so as to expand radially toward the master cylinder 20 described later. Between the outer peripheral edge 34a and the inner peripheral edge 32a, an O-ring 37 for airtightly partitioning the first constant pressure chamber 4a from the outside air is sandwiched between the outer peripheral edge 34a and the inner peripheral edge 32a. Yes.
[0021]
The front member 34 is provided with a cylindrical portion 34b extending toward the inside of the first constant pressure chamber 4a, and the master cylinder 20 is fitted to the cylindrical portion 34b by the bolt 21 and the nut 22 to the inner peripheral side member 34. The piston 23 of the master cylinder 20 is slidably and airtightly inserted, and the base end of the piston 23 abuts and engages the tip of the output rod 14 in the first constant pressure chamber 4a. Yes.
[0022]
The master cylinder 20 includes a thick rear member 24 (inner peripheral member) applied to the inner surface of the front end 32 of the shell 2 so as to cover the opening 33, a front member 34 to which the master cylinder 20 is attached, and the master cylinder 20. Are fixed to the rear member 24 and the front member by being fastened together by the bolt 21 and the nut 22.
[0023]
Here, the inner peripheral edge portion 32 a of the front end portion 32 is sandwiched between the rear member 24 and the outer peripheral edge portion 34 a of the front member 34, whereby the master cylinder 20 is fixed to the shell 2.
[0024]
Reference numeral 25 is a valve spring that supports the control valve 18, 26 is a return spring that biases the input rod 17 to the retracted position, 27 is a return spring that biases the valve body 12 to the retracted position, 28 is a dust boot, 29 Is a reservoir, and 29a is a seal member for sealing between the shell 2 and the master cylinder 20.
[0025]
The pneumatic booster 1 is disposed in the engine room of an automobile, and the axis of the shell 2 is inclined with respect to the horizontal line H so that the input rod 17 side is positioned below the output rod 14 side. A rear end portion is attached to a dash panel (not shown) by a bolt 30, an input rod 17 is inserted into the dash panel and connected to a brake pedal (not shown) in the vehicle compartment, and is connected to the first constant pressure chamber 4a. A negative pressure source, such as an engine intake device, is connected to the communicating joint 31.
[0026]
Next, the operation of the pneumatic booster 1 according to this embodiment will be described. When the input rod 17 is pressed by operating the brake pedal, the atmosphere (positive pressure) is introduced into the first and second variable pressure chambers 4b and 5b via the control valve 18 and connected to the negative pressure source (negative pressure). A pressure difference is generated between the constant pressure chambers 4a and 5a. A thrust is generated in the power pistons 8 and 9 due to this pressure difference, and the valve body 12 moves forward to press the piston 23 of the master cylinder 20 through the reaction disk 13 and the output rod 14 to generate a braking force. When the valve body 12 moves forward, the control valve 18 cuts off the communication between the first and second variable pressure chambers 4b and 5b and the atmosphere, so that the first and second variable pressure chambers 4b and 5b The communication with the atmosphere and the interruption are repeated, and an output corresponding to the input can be obtained with a predetermined boost ratio.
[0027]
At this time, since a part of the reaction force of the output rod 14 that presses the piston 23 of the master cylinder 20 is fed back to the input rod 17 via the reaction disk 13, an operation feeling of the brake pedal corresponding to the braking force is obtained. Can do. When the operating force of the brake pedal reaches a predetermined magnitude, the spring 19a of the reaction force adjusting mechanism 19 is compressed, so that the boost ratio is increased and a large braking force can be generated.
[0028]
When the operation force of the brake pedal is released, the plunger 15 moves backward, and the first and second constant pressure chambers 4a and 5a communicate with the first and second variable pressure chambers 4b and 5b by the control valve 18, and these are externally connected. The pressure difference between the first and second constant pressure chambers 4a, 5a and the first and second variable pressure chambers 4b, 5b disappears, the thrust of the power pistons 8, 9 disappears, and the braking force is released.
[0029]
Next, operation | movement at the time of the vehicle collision of the pneumatic booster 1 of this embodiment is demonstrated.
[0030]
In the pneumatic booster 1 of the present embodiment, when an excessive external force is applied from the master cylinder 20 side at the time of a vehicle collision or the like, the mounting angle is inclined with respect to the horizontal line H. A moment with the tip A of the output rod 14 as the center of rotation is generated between the pressure booster 1 and the pressure booster 1. Since the outer peripheral edge 34a of the front member 34 that fixes the master cylinder 20 is inclined with a predetermined inclination angle so as to expand toward the master cylinder 20, the master cylinder 20 and the air pressure-type multiple When a moment is generated between the force device 1 and the inner peripheral edge 32a of the front end of the shell 2, the outer peripheral edge 34a of the front member 34, and the rear member 24, as shown in FIGS. The outer peripheral edge portion 34a of the upper fixing portion is deformed and the fixing is released, and the master cylinder 20 is rotated around the tip end portion A of the output rod 14 and the shell 2 is deformed. Thereby, the load transmitted to the input rod 17 side can be absorbed and the amount of movement of the brake pedal can be kept small.
[0031]
Here, in the conventional crushable booster, as shown in FIG. 5, the inner peripheral side member and the outer peripheral side member are fixed by rivets or the like, and an excessive external force is applied via the master cylinder at the time of a vehicle collision or the like. In the case of action, the inner peripheral side member is detached from the outer peripheral side member by breaking the rivet or the like. However, in the pneumatic booster of this embodiment, the shell which is the outer peripheral side member Since the outer peripheral member and the inner peripheral member are fixed by sandwiching the inner peripheral portion 32a of the front end portion 32 between the outer peripheral portion 34a and the rear member 24 of the front member 34, a rivet is required. In addition, there is no man-hour for fixing the outer peripheral member and the inner peripheral member with rivets or the like. Moreover, since the inner member and the outer member can be fixed together by fastening the front member 34 and the rear member 24 together with a bolt for attaching the master cylinder, the fixing can be easily performed.
[0032]
Further, in the pneumatic booster according to the present embodiment, the outer peripheral edge 34a of the front member 34 has a predetermined inclination angle so as to expand radially toward the master cylinder 20 side, and thus this inclination angle is adjusted. By doing so, it is possible to freely set the external force for releasing the fixation between the outer peripheral side member and the inner peripheral side member without any increase in the number of parts.
[0033]
In the pneumatic booster of this embodiment, the inner peripheral member is composed of the front member 34 and the rear member 34, and the outer peripheral member is sandwiched between the front member and the rear member. For example, as shown in FIG. 5, the outer peripheral member is composed of a front member 50 and a rear member 51, and the front member 50 and the rear member 51 are fixed by welding or the like to form a single inner member. The outer peripheral end 52a of the peripheral member 52 may be clamped.
[0034]
Further, in the pneumatic booster of the present embodiment, the outer peripheral edge 34a of the front member 34 has a predetermined inclination angle so as to expand radially toward the master cylinder 20 side, and the inner peripheral edge of the front end 32. 32a is assumed to be folded into the first constant pressure chamber 4a side with a predetermined inclination angle. However, in order to freely set the external force for releasing the fixation between the front end portion 32 and the front member 34, the front side It is only necessary that the outer peripheral edge 34a of the member 34 has a predetermined inclination angle.
[0035]
Further, the inner peripheral member is a single member, the outer peripheral end portion is formed in a forked shape by press molding or the like, and a sandwiching portion is provided on the inner peripheral member, and the sandwiching portion is the outer peripheral member. You may make it clamp the inner peripheral edge part of.
[0036]
Contrary to the above, the outer peripheral side member is a single member, the inner peripheral end portion is formed in a forked shape in the cross section by press molding or the like, and the outer peripheral side member is provided with a clamping portion. The outer peripheral end of the peripheral member may be clamped.
[0037]
Furthermore, the inner peripheral member or the outer peripheral member may be composed of three or more members.
[0038]
Further, in the pneumatic booster of the present embodiment, the front member 34 is provided with the cylindrical portion 34b on which the piston 23 side of the master cylinder 20 is fitted. A cylinder portion is provided in which the piston 23 side of the cylinder 20 is fitted, a hole through which the master cylinder 20 penetrates in the axial direction is provided in the front member 34, and the master cylinder 20 penetrates the hole in the front member 34 to the rear member 24. You may make it fit in the provided cylindrical part.
[0039]
In the pneumatic booster of the present embodiment, a so-called tandem type pneumatic booster having two sets of constant pressure chambers and variable pressure chambers is used, but the present invention is not limited to this, and the constant pressure chambers and the variable pressure chambers May be one set or three or more sets.
[0040]
【The invention's effect】
As described above, according to the first aspect of the present invention, either the inner peripheral member or the outer peripheral member is composed of a plurality of members, and the periphery of the other member is secured by fixing the plurality of members together. Since it is possible to fix the outer peripheral member and the inner peripheral member without using a rivet or the like by adopting a configuration that sandwiches the end portion, man-hours for fixing the inner peripheral member and the outer peripheral member. In addition , the number of parts for fixing can be reduced.
[0041]
Furthermore, the assembly process of fixing the inner peripheral member and the outer peripheral member is facilitated.
[0042]
According to the present invention of claim 2 , the master cylinder and the plurality of inner peripheral members are fixed to each other by the same bolt, thereby fixing the plurality of inner peripheral members to each other without increasing the number of parts. In addition, it is possible to reduce the number of steps for fixing the inner peripheral members separately.
[0043]
Further, according to the present invention of claim 3, by an outer peripheral end portion of the inner peripheral member has a structure having a predetermined inclination angle so as to have a radiate As towards the master cylinder, when assembled The positioning of the outer peripheral member and the inner peripheral member can be freely set by adjusting the inclination angle.
[Brief description of the drawings]
FIG. 1 is a sectional view of an embodiment of a pneumatic booster according to the present invention, taken along an axial direction of the pneumatic booster.
2 is a partially enlarged view of the pneumatic booster of FIG. 1;
3 is a partial enlarged view of the pneumatic booster of FIG. 1 just before the fixation between the inner peripheral member and the outer peripheral member is released due to an external force applied from the master cylinder side.
4 is a partially enlarged view of the pneumatic booster of FIG. 1 at the moment when the external force is applied from the master cylinder side and the fixation between the inner peripheral member and the outer peripheral member is released.
FIG. 5 is a partially enlarged view of another embodiment of a pneumatic booster according to the present invention.
FIG. 6 is a cross-sectional view along the axial direction of a conventional pneumatic booster.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Atmospheric pressure booster 2 Shell 3 Bulkhead 4 Front chamber 4a First constant pressure chamber 4b First variable pressure chamber 5 Rear chamber 5a Second constant pressure chamber 5b Second variable pressure chamber 6 Diaphragm 7 Diaphragm 8 Power piston 9 Power piston 10 Passage 11 Passage 12 Valve body 13 Reaction disk 14 Output rod 15 Plunger 16 Dust seal 17 Input rod 18 Control valve 19 Reaction force adjustment mechanism 19a Compression spring 20 Master cylinder 21 Bolt 22 Nut 23 Piston 24 Rear member (inner peripheral side member)
25 Valve spring 26 Return spring 27 Return spring 28 Dust boot 29 Reservoir 29a Seal member 30 Bolt 31 Joint 32 Front end (outer peripheral member)
32a Inner peripheral edge (peripheral edge)
32b Recess 33 Opening 34 Front member (inner peripheral member)
34a Outer peripheral edge 34b Cylindrical portion 37 O-ring 50 Front member (outer peripheral member)
51 Rear member (outer member)
52 Inner peripheral member 52a Outer peripheral end

Claims (3)

The inside of the shell is defined by a power piston into a constant pressure chamber and a variable pressure chamber, gas is introduced into the variable pressure chamber according to the input to the input rod, and the pressure difference generated between the constant pressure chamber and the variable pressure chamber In a pneumatic booster that generates thrust in a power piston and operates a piston of a master cylinder attached to one surface side of the shell via an output rod by the thrust of the power piston, the one surface side of the shell Has an annular outer peripheral member having an opening at substantially the center, and an inner peripheral member that covers the opening of the outer peripheral member and to which the master cylinder is attached. The inner peripheral member or the outer peripheral member One of the members is composed of a plurality of members, and the peripheral members of the other member are clamped by fixing the plurality of members to each other. Before Kifuku number of members is the inner circumference side member, said master cylinder and the plurality of inner peripheral member, pneumatic booster according to claim 1, wherein Rukoto are fixed to each other by the same bolts apparatus. Outer peripheral end portion of the front Symbol inner circumference side member, said master cylinder pneumatic booster according to claim 2, wherein Rukoto to have a predetermined inclination angle so as to have a radiate toward the.

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