JP2006341790A - Booster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a booster with high quietness generating no contact sound made by contacting/leaving of a wire material even if a coil spring is vibrated by closely attaching the wire material of first winding and second winding of the coil spring over a predetermined range. <P>SOLUTION: When a transformation chamber is communicated with atmosphere (or pressure air source) or a constant pressure chamber by a valve mechanism, a differential pressure is generated or disappears between the transformation chamber and the constant pressure chamber, a dividing member compresses the coil spring or it is retreated to a non-operation position by stretching of the coil spring. When the coil spring is rapidly compressed or stretched, it is vibrated. In the first winding of the coil spring, the wire material is wound a flat plane perpendicular to a coil axis and in the second winding in which a wire material gap with the first winding becomes narrow, the first winding and the wire material are closely attached from an end of the wire materia to a predetermined range. Therefore, even if the coil spring is vibrated, the wire material is contacted/left and the contact sound is not generated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a booster for a vehicle, and more particularly to a booster with improved quietness.

  In general, in a negative pressure type booster, a booster shell is divided into a variable pressure chamber and a constant pressure chamber by a diaphragm, a valve piston is fixed to the diaphragm, and a plunger is fitted to the valve piston. The front end portion of the plunger penetrates the base end portion of the valve piston and pushes the master piston of the master cylinder. The rear end portion is rotatably connected to the input rod within the cylindrical portion of the valve piston, and is connected to the brake pedal via the input rod. A valve mechanism is provided that communicates and shuts off the variable pressure chamber to the constant pressure chamber and the atmosphere based on relative movement between the valve piston and the plunger. A coil spring is interposed between the valve piston and the front-side inner surface of the booster shell so that the valve piston, the diaphragm and the like are retracted to the non-operating position.

  The coil spring wire is wound on a plane perpendicular to the coil axis by a little less than one turn, and is wound spirally from the front of the end of the wire in accordance with the lead. Accordingly, when the coil spring is interposed between the valve piston and the front side inner surface of the booster shell in a state where a set load is applied, as shown in FIG. 4, the start portion 53 of the second winding 52 of the coil spring 50 is obtained. Rides on the end 55 of the wire 54, and the wire 54 of the second roll 52 approaches the wire of the first roll 51 due to the twist angle caused by the torsional moment, and is bent in a curved shape with the end 55 as a fulcrum by the set load. The first gap 51 is gradually separated from the wire 54 of the first winding 51 by the minute gap 56 separated from the end 55.

For this reason, when the brake pedal is actuated suddenly and the coil spring 50 is suddenly compressed or expanded, the coil spring 50 vibrates and the wire 54 of the second winding 52 becomes the wire of the first winding 51 in the minute gap 56. A contact sound is generated in contact with and away from 54. In order to prevent the contact sound of the coil spring wire, in the negative pressure booster described in Patent Document 1, the end of the coil spring is covered with a rubber cover 13.
International Publication No. 02/43998 pamphlet (4th, 5th page, FIG. 1)

  However, in the one described in Patent Document 1 described above, the end of the coil spring is covered with a rubber cover to prevent contact noise of the wire due to vibration at the end of the coil spring. A separate cover is required, which increases costs. Furthermore, when the rubber deteriorates with time and the elasticity decreases, the ability to attenuate the vibration of the coil spring decreases, and noise generated from the coil spring cannot be reduced.

  In the present invention, the first and second winding wires of the coil spring are brought into close contact with each other over a predetermined range, so that even if the coil spring vibrates, no contact noise is generated due to the contact and separation of the wires. The object is to provide a booster.

  In order to solve the above-mentioned problem, the structural feature of the invention according to claim 1 is that the booster shell (1) is partitioned into a variable pressure chamber (6) and a constant pressure chamber (5) by a partition member (4), The base end (8a) of the valve piston (8) is fixed to the partition member, and the output of the partition member based on the pressure difference between the variable pressure chamber and the constant pressure chamber is a reaction member (from the valve piston to the output rod (14)). 17), the plunger (21) that is transmitted via the reaction force member in cooperation with the input rod (23) moved in the axial direction by the brake pedal (25), and is connected to the valve piston and the plunger. And a valve mechanism (30) for communicating and shutting off the variable pressure chamber to the constant pressure chamber and the atmosphere or a pressure air source based on relative movement between the valve piston and the front-side inner surface of the booster shell. In booster coil spring (16) is interposed,

  In the wire rod (40) of the coil spring (16), the first roll (41) is wound in a plane perpendicular to the coil axis (42), and the second roll (43) is predetermined from the end (44) of the wire rod. That is, the first winding and the wire are wound in close contact over the range (L).

  The structural feature of the invention according to claim 2 is that, in the first aspect, the wire (40) of the coil spring (16) is arranged such that the first turn (41) is the coil axis (42) in the free state of the coil spring. It is wound in a flat plane, and the second roll (43) is wound in close contact with the first roll and the wire from the end (44) of the wire over a predetermined range (L).

  The structural feature of the invention according to claim 3 is that, in claim 1 or claim 2, the coil spring (16) has a beer barrel shape in which the diameter of the central portion is larger than the diameters of both end portions.

  According to the invention according to claim 1 configured as described above, when the variable pressure chamber is communicated to the atmosphere (or a pressure air source) or the constant pressure chamber by the valve mechanism, a differential pressure is generated between the variable pressure chamber and the constant pressure chamber. Created or disappeared, the partition member compresses the coil spring or is retracted to the inoperative position by extension of the coil spring. The coil spring vibrates when it is suddenly compressed or extended, but the first winding of the coil spring is wound on a plane perpendicular to the coil axis, and the first winding and the second winding where the distance between the wires is narrowed are the ends of the wire. Since the first wire and the wire are in close contact with each other over a predetermined range from the part, the wire does not come in contact with or separate from the coil spring even when the coil spring vibrates, and the silence during operation of the booster is reduced. Can be increased.

  According to the invention according to claim 2 configured as described above, since the second winding of the coil spring is in close contact with the first winding over the predetermined range from the end of the wire in a free state, the coil spring It is possible to surely prevent the wire from coming into contact with each other and generating a contact sound even if it vibrates.

  According to the invention according to claim 3 configured as described above, the first and second windings of the coil spring are brought into contact with and separated from each other by suppressing the occurrence of vibration by making the coil spring into a beer barrel shape. Further, it can be effectively prevented.

  Hereinafter, embodiments of a booster according to the present invention will be described with reference to the drawings. As shown in FIG. 1, a booster shell 1 is composed of a front shell 2 and a rear shell 3, and a flexible diaphragm 4 is hermetically sandwiched between the shells 2 and 3 by a bead at the outer peripheral edge. 1 is partitioned into a constant pressure chamber 5 and a variable pressure chamber 6. A disk-shaped plate 7 is superposed on the diaphragm 4 on the constant pressure chamber 5 side, and the outer peripheral surface of the base end portion 8a of the cylindrical valve piston 8 is airtightly fixed to the diaphragm 4 and the plate 7 so that the base end portion 8a is fixed. Is exposed to the constant pressure chamber 5. A negative pressure introduction pipe 10 is attached to the front shell 2, and the constant pressure chamber 5 is communicated with the intake manifold of the engine via the negative pressure introduction pipe 10 so that the negative pressure is always maintained during engine operation.

  As shown in FIG. 2, the center portion of the rear shell 3 is bent outward, a cylindrical protruding portion 3a protrudes rearward, and a through hole 3b is formed on the axis. The valve piston 8 has a cylindrical portion 8b protruding rearward from the base end portion 8a, and the cylindrical portion 8b protrudes rearward from the protruding portion 3a of the rear shell 3 through the through hole 3b. A seal 9 is interposed between the inner peripheral surface of the through-hole 3b and the outer peripheral surface of the cylindrical portion 8b to block the variable pressure chamber 6 from the atmosphere.

  As shown in FIG. 1, the master cylinder 11 has a rear end portion 11a that passes through a central hole formed in the front shell 2 and protrudes into the constant pressure chamber 5 in an airtight manner. It is in contact with the front surface of the shell 2. The front shell 2 and the rear shell 3 are joined by a plurality of, for example, two tie rods 12 extending in parallel with the axis at a substantially intermediate position between the axis and the outer periphery of the booster shell 1 constituted by both shells. 11 is fixed.

  A master piston 13 is fitted to the master cylinder 11 so as to be slidable in the front-rear direction. The master piston 13 projects from the rear end portion of the master cylinder 11 into the constant pressure chamber 5 and extends to the vicinity of the front end face of the valve piston 8. An output rod 14 is interposed between the valve piston 8 and the master piston 13. The valve piston 8 transmits the output of the diaphragm 4 based on the pressure difference between the constant pressure chamber 5 and the variable pressure chamber 6 to the output rod 14 via the reaction member 17, and the output rod 14 pushes the master piston 13 forward. To do. A coil spring 16 is interposed between the front shell 2 and the front end face of the valve piston 8 with a set load applied thereto, and biases the valve piston 8 backward. The coil spring 16 has a beer barrel shape in which the diameter of the central portion is larger than the diameters of both end portions, thereby improving stability against load and vibration proofing.

  As shown in FIG. 3, in the wire rod 40 of the coil spring 16, the first winding 41 is wound on a plane perpendicular to the coil axis 42 in the free state of the coil spring, and the second winding 43 is predetermined from the end 44 of the wire rod 40. The first roll 41 and the wire 40 are wound in close contact over the range L, and then gradually separated from the first roll. The wire 40 is similarly wound at both ends of the coil spring 16.

  As shown in FIG. 2, the valve piston 8 has a reaction force chamber hole 8c from the front end surface toward the rear end surface, a small diameter reaction force hole 8d that opens to the reaction force chamber hole 8c, and a medium diameter continuous to the reaction force hole 8d. The intermediate hole 8h and the valve body storage hole 8e having a diameter larger than that of the intermediate hole 8h are sequentially drilled on the axis. An annular groove 8f is formed on the bottom surface of the reaction force chamber hole 8c in the axial direction so that the outer peripheral surface of the reaction force chamber hole 8c is shared with the inner peripheral surface of the reaction force chamber hole 8c. An annular protrusion 14a formed at the end is fitted so as to be relatively movable in the axial direction. A reaction force chamber 15 is formed between the annular protrusion 14a and the bottom surface of the reaction force chamber hole 8c, and a disk-shaped reaction force member 17 formed of an elastic material is accommodated in the reaction force chamber 15.

  Reference numeral 21 denotes a plunger in which the distal end shaft portion 21 a is slidably fitted in the reaction force hole 8 d, and the distal end surface faces the rear end surface of the reaction force member 17. Reference numeral 22 denotes an H-shaped key member, the insides of the straight portions on both sides enter into an annular groove 21c formed in the plunger 21, and both ends are inserted into rectangular holes 8g formed in the radial direction of the valve piston 8. The outer surface of the straight portion slides and extends to the outside. As a result, the valve piston 8 and the plunger 21 can move relative to each other in the axial direction by a distance obtained by subtracting a distance obtained by adding twice the thickness of the key member 22 from the distance obtained by adding the widths of the rectangular hole 8g and the annular groove 21c. it can.

  An input rod 23 is rotatably connected to the rear end of the plunger 21, and the input rod 23 extends rearward from the cylindrical portion 8 b through a filter 24 that prevents passage of dust and the like and a silencer 27 having a sound absorbing function. The brake pedal 25 (see FIG. 1) is connected. A bellows 26 is fixed between the input rod 23 and the protruding portion 3 a of the rear shell 3 and covers the outer periphery of the cylindrical portion 8 b of the valve piston 8. A plurality of circumferentially vent holes 26 a are opened on the end face of the bellows 26, and outside air is introduced into the valve piston 8 through the silencer 27 and the filter 24 from the vent holes 26 a.

  The valve mechanism 30 for switching the variable pressure chamber 6 to the constant pressure chamber 5 or the atmosphere to communicate with the pressure chamber 5 has an annular negative pressure valve seat 8i formed in the step portion 8k between the intermediate hole 8h of the valve piston 8 and the valve body housing hole 8e. Have. The annular negative pressure valve seat 8i is formed such that the end surface of the step portion 8k is inclined forward and outward, and the inclined end surface and the inner peripheral surface of the intermediate hole 8h are connected by an arc. A passage 8j that opens to the valve housing hole 8e outside the negative pressure valve seat 8i passes through the side wall of the valve piston 8 and opens to the constant pressure chamber 5. An atmospheric valve seat 21b is formed on the rear end surface of the plunger 21 inside the negative pressure valve seat 8i. A disc-like valve body 31 is loosely fitted in the valve body storage hole 8e so as to be movable in the front-rear direction. A negative pressure valve 31a is formed on the front end surface of the valve body 31 to connect and block the variable pressure chamber 6 and the constant pressure chamber 5 in contact with and away from the negative pressure valve seat 8i. An atmospheric valve 31b is provided in a ring shape inside the negative pressure valve 31a on the front end surface of the valve body 31, and the atmospheric valve seat 21b is in contact with and separated from the atmospheric valve 31b to communicate and block the variable pressure chamber 6 and the atmosphere.

  The rear end of the valve body 31 is connected to an annular holding body 35 by a bellows 34 that allows the valve body 31 to move in the axial direction. The holding body 35 is pressed against the step formed in the valve body housing hole 8e by the spring force of the compression spring 38 interposed between the retainer 37 locked to the central portion of the input rod 23. A compression spring 39 is interposed between the rear end surface of the valve body 31 and the shoulder portion formed on the input rod 23 to urge the valve body 31 forward with respect to the input rod 23. Thereby, when the brake is not operated, the atmospheric valve seat 21b is brought into contact with the atmospheric valve 31b to cut off the communication between the variable pressure chamber 6 and the atmosphere, and the negative pressure valve 31a is slightly separated from the negative pressure valve seat 8i. The variable pressure chamber 6 and the constant pressure chamber 5 are communicated with each other while being held in position.

  Next, the operation of the booster according to the above-described embodiment will be described. When the brake pedal 25 is operated, the plunger 21 is advanced against the spring force of the compression spring 38 by the input rod 23, and the valve body 31 is advanced by the spring force of the compression spring 39. As a result, the negative pressure valve 31a comes into contact with the apex portion of the arc-shaped negative pressure valve seat 8i, and the communication between the variable pressure chamber 6 and the constant pressure chamber 5 is blocked.

  When the plunger 21 is further advanced, the atmosphere valve seat 21b and the atmosphere valve 31b are separated, and the atmosphere introduced into the valve piston 8 through the silencer 27 and the filter 24 passes through the intermediate chamber 8h, the rectangular hole 8g, and the like. And flows into the variable pressure chamber 6. As a result, a pressure difference is generated between the variable pressure chamber 6 and the constant pressure chamber 5, and the valve piston 8 moves forward by compressing the coil spring 16 due to the pressure difference between the two chambers 5 and 6 acting on the diaphragm 4. The reaction member 17 is elastically deformed with an operating force corresponding to the difference, and the master piston 13 is pushed through the output rod 14. At this time, the coil spring 16 vibrates considerably when compressed particularly rapidly, but the second winding 43 is in close contact with the first winding 41 and the wire 40 over a predetermined range L from the end portion 44 of the wire 40. Since it is wound and then gradually separated from the first roll, the second winding wire 40 does not come into contact with or separate from the first winding wire 40 due to vibration, and no contact sound is generated.

  The reaction force member 17 is elastically deformed by being pressed by the valve piston 8, and the reaction force member 17 flows into the reaction force hole 8d and presses the distal end portion of the distal end shaft portion 21a of the plunger 21 backward, whereby the plunger 21 is moved. The air valve seat 21b is retracted and seated on the air valve 31b to cut off the communication between the air and the variable pressure chamber 6, and the brake hydraulic pressure corresponding to the depression force of the brake pedal 25 is generated and held in the master cylinder 11. At this time, the force of stepping on the brake pedal 25 is transmitted from the tip shaft portion 21a of the plunger 21 to the reaction force member 17 via the input rod 23, and the reaction force member 17 is elastically deformed according to the depression force. You can feel the reaction force.

  When the brake pedal 25 is released after the brake operation, the plunger 21 is moved rearward with respect to the valve piston 8 by the spring force of the compression spring 38, and the valve body is in a state where the atmospheric valve seat 21b is in contact with the atmospheric valve 31b. 31 is moved rearward relative to the valve piston 8 against the spring force of the compression spring 39, and the negative pressure valve 31a is separated from the negative pressure valve seat 8i. As a result, the negative pressure in the constant pressure chamber 5 is introduced into the variable pressure chamber 6 through the passage 8j, the pressure difference between the variable pressure chamber 6 and the constant pressure chamber 5 is eliminated, and the valve piston 8, the plate 7 and the diaphragm 4 are coiled. While being moved rearward by the spring force of the spring 16, the master piston 13 is moved rearward and the hydraulic pressure in the master cylinder 11 is lost.

  At this time, the coil spring 16 vibrates considerably particularly when the brake pedal 25 is suddenly released and suddenly extended. However, the second winding 43 is wound once from the end 44 of the wire 40 over a predetermined range L. Since the eye 41 and the wire 40 are wound in close contact with each other and then gradually separated from the first roll, the second wire 40 comes into contact with and separates from the first wire 40 due to vibration and generates a contact sound. There is nothing.

  The plunger 21 stops at the same time as the key member 22 contacts the inner surface of the step portion of the protrusion 3 a of the rear shell 3, and the valve piston 8 stops by contacting the key member 22. As a result, the negative pressure valve 31a is very close to the negative pressure valve seat 8i when the brake is not operated. When the brake is applied, the negative pressure valve 31a quickly contacts the negative pressure valve seat 8i due to the forward movement of the valve body 31. Can do. By retreating until the valve piston 8 contacts the key member 22 after the plunger 21 stops, the negative pressure valve seat 8i is retreated to a position slightly away from the negative pressure valve 31a.

  In the above embodiment, the wire 40 of the coil spring 16 is wound in a plane perpendicular to the coil axis 42 in the free state of the coil spring 16, and the second roll 43 is predetermined from the end 44 of the wire 40. The first winding 41 and the wire 40 are tightly wound over the range L, but the coil spring 16 is interposed between the front shell 2 and the front end surface of the valve piston 8 with a set load interposed therebetween. The first roll 41 is wound in a plane perpendicular to the coil axis 42, and the second roll 43 is wound in close contact with the first roll 41 and the wire 40 over a predetermined range L from the end 44 of the wire 40. You may do it.

  The coil spring 16 is not limited to a beer barrel shape, and may be a cylindrical shape or a truncated cone shape.

  In the above embodiment, the constant pressure chamber 5 communicates with the intake manifold of the engine and is maintained at a negative pressure, and the variable pressure chamber 6 is controlled by the valve mechanism (30) based on the relative movement between the valve piston and the 8 plunger 21. The constant pressure chamber is maintained in the atmosphere, and the variable pressure chamber is connected to a constant pressure air source such as an air pump through a valve mechanism, and the valve piston and the 8 plunger 21 are moved relative to each other. Based on the above, the variable pressure chamber 6 may be communicated with the constant pressure chamber 5 and the pressure air source by the valve mechanism (30) and shut off.

Sectional drawing which shows embodiment of the booster which concerns on this invention. FIG. 2 is an enlarged cross-sectional view of a valve mechanism portion taken along the line AA in FIG. The elements on larger scale which show the edge part of a coil spring. The elements on larger scale which show the edge part of the conventional coil spring.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Booster shell, 2 ... Front shell, 3 ... Rear shell, 4 ... Diaphragm (partition member), 5 ... Constant pressure chamber, 6 ... Variable pressure chamber, 8 ... Valve piston, 8b ... Cylindrical part, 8i ... Negative pressure valve seat, 11 ... Master cylinder, 13 ... Master piston, 14 ... Output rod, 15 ... Reaction force chamber, 16 ... Coil spring, 17 ... Reaction force member, 21 ... Plunger, 21b ... Air valve seat, 22 ... Key member, 23 ... Input Rod, 25 ... Brake pedal, 30 ... Valve mechanism, 31 ... Valve body, 31a ... Negative pressure valve, 31b ... Air valve, 38, 39 ... Compression spring, 40 ... Wire rod, 41 ... First turn, 42 ... Coil axis, 43 ... 2nd roll, 44 ... end, L ... predetermined range.

Claims (3)

The booster shell (1) is partitioned into a variable pressure chamber (6) and a constant pressure chamber (5) by a partition member (4), and a base end portion (8a) of the valve piston (8) is fixed to the partition member, Plunger (21), wherein the output of the partition member based on the pressure difference between the chamber and the constant pressure chamber is transmitted from the valve piston to the output rod (14) via the reaction member (17) and acts in cooperation with the reaction member. ) Is connected to an input rod (23) which is moved in the axial direction by a brake pedal (25), and the variable pressure chamber and the atmosphere or pressure air source are made to be based on relative movement of the valve piston and the plunger. A booster comprising a valve mechanism (30) for communicating and blocking, and a coil spring (16) interposed between the valve piston and a front-side inner surface of the booster shell,
In the wire rod (40) of the coil spring (16), the first roll (41) is wound in a plane perpendicular to the coil axis (42), and the second roll (43) is predetermined from the end (44) of the wire rod. The negative pressure booster, wherein the first roll and the wire are wound in close contact over a range (L). The wire (40) of the coil spring (16) according to claim 1, wherein the first winding (41) is wound in a plane perpendicular to the coil axis (42) in the free state of the coil spring, and the second winding (43). The negative pressure booster is characterized in that the first roll and the wire are wound in close contact over a predetermined range (L) from the end (44) of the wire. 3. The booster according to claim 1, wherein the coil spring (16) has a beer barrel shape in which the diameter of the central portion is larger than the diameters of both end portions.

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