JP2020037316A - Tandem type negative pressure booster and method of assembling sleeve - Google Patents

Abstract

To enhance mass productivity by improving an assembling property of a sleeve, and to enhance flexibility in material selection of the sleeve, in a tandem type negative pressure booster in which the sleeve fixed to one of a partition plate and a rear portion diaphragm airtightly penetrates the other of the partition plate or the rear portion diaphragm, and a tie rod inserted in the sleeve is fixed between a front portion shell half body and a rear portion shell half body.SOLUTION: An annular grommet 65 attached to a side where a sleeve 45 airtightly penetrates among a partition plate 10 and a rear portion diaphragm 19, is elastically slid with an outer periphery of the sleeve 45. With an annular fitting portion 66 made from elastic material that is fixed to a side where the sleeve 45 is fixed among the partition plate 10 and the rear portion diaphragm 19, the sleeve 45 is fitted so as to make an inner periphery of the annular fitting portion 66 elastically contact with the outer periphery of the sleeve 45.SELECTED DRAWING: Figure 2

Description

  The present invention provides a booster shell including a front shell half and a rear shell half combined with each other, a partition plate coupled to the booster shell while partitioning the booster shell into a front shell chamber and a rear shell chamber. A front booster piston housed in the front shell chamber so as to be able to reciprocate back and forth, and the front booster while dividing the front shell chamber into a front front negative pressure chamber and a rear front working chamber. A front diaphragm connected to a rear surface of a piston and supported by the booster shell; a rear booster piston housed in the rear shell chamber so as to be able to reciprocate back and forth; and a rear negative pressure chamber in the front of the rear shell chamber. A rear diaphragm bound to the rear surface of the rear booster piston while being partitioned into a rear working chamber on the rear side and supported by the booster shell; A cylindrical sleeve fixed to one of the rear diaphragms and airtightly penetrating the other of the partition plate and the rear diaphragm, and an annular passage connecting the front working chamber and the rear working chamber to the sleeve. A tandem-type negative pressure booster comprising a tie rod formed between the front shell half and the rear shell half and inserted through the sleeve, and a sleeve for manufacturing the tandem type negative pressure booster. To a sleeve assembling method for assembling the sleeve.

  Such a tandem-type negative pressure booster is already known, for example, from Patent Document 1.

JP 2004-58959 A

  However, in the structure disclosed in Patent Document 1, the end of the cylindrical sleeve on the side of the partition plate is press-fitted and fixed to the partition plate. In such a structure, the assemblability of the sleeve is reduced. Not only is it not excellent, there is a problem in mass productivity, but also the material of the sleeve is limited to metal, resulting in high cost.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a tandem-type negative pressure booster capable of improving mass productivity by increasing the assemblability of a sleeve and increasing the degree of freedom in selecting a material of a sleeve, and assemblability of a sleeve. It is an object of the present invention to provide a sleeve assembling method capable of enhancing the sleeve.

  In order to achieve the above object, the present invention provides a booster shell comprising a front shell half and a rear shell half combined with each other, and the booster shell which partitions the inside of the booster shell into a front shell chamber and a rear shell chamber. A partition plate connected to the shell, a front booster piston housed in the front shell chamber so as to be able to reciprocate back and forth, and a front negative pressure chamber and a rear front working chamber in the front shell chamber. A front diaphragm bound to the rear surface of the front booster piston and supported by the booster shell, a rear booster piston housed in the rear shell chamber so as to be able to reciprocate back and forth, and the rear shell A rear part which is bound to the rear surface of the rear booster piston and is supported by the booster shell while partitioning the room into a front rear negative pressure chamber and a rear rear working chamber. An earphone, a cylindrical sleeve fixed to one of the partition plate and the rear diaphragm and airtightly penetrating the other of the partition plate and the rear diaphragm, and connecting the front working chamber and the rear working chamber. A tandem-type negative-pressure booster comprising: an annular passage formed between the sleeve and the sleeve; and a tie rod inserted through the sleeve and fixed between the front shell half and the rear shell half. And an annular grommet attached to the other of the rear diaphragms is resiliently slidably contacting the outer periphery of the sleeve, and an annular fitting made of an elastic material fixed to the one of the partition plate and the rear diaphragm. The sleeve so that the inner periphery of the annular fitting portion resiliently contacts the outer periphery of the sleeve. That is fitted to the first feature.

  In addition, in the present invention, in addition to the configuration of the first aspect, the annular fitting portion is formed integrally with the rear diaphragm, and the sleeve is a cylindrical portion fitted to the annular fitting portion. A flange portion which protrudes radially outward from the rear diaphragm side end of the cylindrical portion and faces the rear working chamber end of the annular fitting portion, and radially outward from the outer periphery of the cylindrical portion. An annular retaining projection protruding and facing an end of the annular fitting portion on the side of the rear negative pressure chamber, wherein the annular retaining portion is provided on the outer periphery of the cylindrical portion between the flange portion and the retaining projection. A second feature is that an annular fitting recess for fitting the fitting portion is formed.

  The present invention, in addition to the configuration of the second aspect, further includes an end on the rear shell half side of the tie rod, the rear portion facing the flange portion of the sleeve while being in contact with an inner surface of the rear shell half. A flange fixed to the shell half is integrally formed, and through holes communicating with the annular passage are provided at a plurality of circumferential positions of the flange formed to have a larger diameter than the flange. A third feature is that an outer end of the through-hole along a radial direction is disposed outside the outer periphery of the flange portion on a projection view on a plane orthogonal to an axis of the tie rod and the sleeve. I do.

  A fourth feature of the present invention is that, in addition to any one of the first to third features, the sleeve is made of resin.

  Further, the present invention is a sleeve assembling method for assembling the sleeve at the time of manufacturing a tandem type negative pressure booster having any one of the first to fourth features, wherein a first method of attaching the grommet to the partition plate is provided. And a front diaphragm connected to the rear surface of the front booster piston, the partition plate to which the grommet is attached, and the rear surface of the rear booster piston integrally having the annular fitting portion. A second step of assembling the rear diaphragm with the other, and a third step of resiliently fitting the sleeve into the annular fitting portion by inserting the sleeve from the rear diaphragm side and inserting the sleeve through the grommet. The fifth feature is that the execution is performed in order.

  According to the first aspect of the present invention, the inner periphery of the annular fitting portion is elastically brought into contact with the annular fitting portion made of an elastic material fixed to one of the partition plate and the rear diaphragm. The sleeve is fixed to one of the partition plate and the rear diaphragm by fitting the sleeve in this manner, and the annular grommet attached to the other of the partition plate and the rear diaphragm resiliently slides on the outer periphery of the sleeve. Compared with the press-fitting method, the assembling property is improved, and as a result, mass productivity can be improved. Moreover, it is not necessary to limit the material of the sleeve to metal, and the degree of freedom in selecting the material of the sleeve can be increased.

  Further, according to the second aspect of the present invention, the annular fitting portion integrally formed by the rear diaphragm is disposed in the fitting concave portion between the flange portion of the sleeve and the annular retaining projection, so that the rear diaphragm is activated during operation. The sleeve can be reliably prevented from slipping out of the sleeve.

  According to the third feature of the present invention, since the flange portion of the sleeve is disposed so as to face the flange portion integrally formed on the rear shell half-side end of the tie rod, Even if the flange portion abuts against the flange portion due to tolerance, the outer ends of the through holes provided at a plurality of circumferential positions of the flange portion having a larger diameter than the flange portion and communicating with the annular passage in the sleeve may have the tie rod and the sleeve. Since the projection is located outside the outer periphery of the flange on a projection onto a plane perpendicular to the axis of the rear part, the space between the rear working chamber and the annular passage is not interrupted.

  According to the fourth feature of the present invention, the sleeve can be made of resin, so that the cost can be reduced.

  Further, according to a fifth aspect of the present invention, in assembling the sleeve, a first step of attaching a grommet to the partition plate; a front diaphragm attached to the front booster piston; and a partition plate having the grommet attached. A second step of mutually assembling a rear diaphragm bonded to the rear surface of the rear booster piston while integrally having an annular fitting portion; and inserting a sleeve from the rear diaphragm side to resiliently engage the annular fitting portion. And a third step of fitting and inserting through the grommet; in this order, a simple and highly mass-producing assembling method can be realized.

It is a longitudinal section of a tandem type negative pressure booster. FIG. 2 is an enlarged view of a portion indicated by an arrow 2 in FIG. 1. It is a perspective view of a sleeve. It is a longitudinal cross-sectional view which shows the state in the 1st process at the time of sleeve assembly. It is a longitudinal cross-sectional view which shows the state in the 2nd process at the time of sleeve assembly. It is a longitudinal section showing the state in the 3rd process at the time of sleeve assembly.

  The embodiment of the present invention will be described below with reference to the accompanying drawings. First, in FIG. 1, the front surface of the booster shell 5 of the tandem type negative pressure booster B is amplified and driven by the tandem type negative pressure booster B. Attached to the cylinder body 6 of the brake master cylinder M.

  The booster shell 5 comprises a front shell half 7 and a rear shell half 8 mutually connected. A rear end of the front shell half 7 is formed so as to surround a front end of the rear shell half 8, and a first cylindrical member fixed to a front outer periphery of the rear shell half 8. The outer periphery of the annular plate portion 9a provided in the front shell half 7 closes the annular space created between the rear end of the front shell half 7 and the front end of the rear shell half 8 from behind. Joined to the back end.

  The inside of the booster shell 5 is divided into a front shell chamber 12 and a rear shell chamber 13 by a partition plate 10 connected to the booster shell 5. A front end of a second cylindrical member 11 is fixed to the outer periphery of the partition plate 10, and a rear end of the second cylindrical member 11 is connected to a rear end of the front shell half 7. Thereby, the partition plate 10 is connected to the booster shell 5.

  A front booster piston 14 is accommodated in the front shell chamber 12 so as to be able to reciprocate back and forth. On the rear surface of the front booster piston 14, a front negative pressure chamber is provided in the front shell chamber 12. A front diaphragm 15 partitioned into a front working chamber 16 and a rear front working chamber 17 is attached. The front diaphragm 15 has an annular first outer bead portion 15 a at the outer peripheral edge thereof, and is provided between the outer periphery of the front end of the second tubular member 11 and the front shell half 7. The front diaphragm 15 is supported by the booster shell 5 by sandwiching the first outer peripheral bead portion 15a. The front negative pressure chamber 16 is connected to a negative pressure source V (for example, inside an intake manifold of an internal combustion engine) via a negative pressure introducing pipe 4 connected to the front shell half 7.

  A rear booster piston 18 is accommodated in the rear shell chamber 13 so as to be able to reciprocate back and forth. On the rear surface of the rear booster piston 18, the rear shell chamber 13 has a front rear negative pressure chamber 20 and a rear A rear diaphragm 19 partitioned into a rear working chamber 21 is attached. The rear diaphragm 19 has an annular second outer bead portion 19a at its outer peripheral edge, and is provided between the outer periphery of the first tubular member 9 and the inner periphery of the rear end of the second tubular member 11. The rear diaphragm 19 is supported by the booster shell 5 by sandwiching the second outer peripheral bead portion 19a between the first and second outer bead portions 19a.

  The front booster piston 14 and the front diaphragm 15 have a cylindrical boss portion 23 slidably supported by the partition plate 10 with an annular sealing member 22 interposed between the front booster piston 14 and the front diaphragm 15. The rear booster piston 18 and the rear diaphragm 19 are connected to the outer periphery of the rear end of the boss 23.

  At the center of the rear wall of the rear shell half 8, a front end of a rear extension cylinder 8a extending rearward is coaxially and integrally connected to the rear extension cylinder 8a, and slides on the rear extension cylinder 8a via a seal member 26. The front end portion of the freely supported valve cylinder portion 24 is coaxially and integrally connected to the rear end portion of the boss portion 23 so as to form a piston boss 25 together with the boss portion 23. Is formed of a synthetic resin.

  In the valve cylinder portion 24, a valve piston 27, an input rod 28 connected to the valve piston 27, and front and rear working chambers 17, 21 in accordance with the forward and backward movements of the input rod 28 are provided. A control valve 29 for switching communication between the rear negative pressure chambers 16 and 20 and the atmosphere is provided, and a brake pedal P is connected to a rear end of the input rod 28.

  The valve piston 27 is slidably fitted in a guide hole 30 provided in the valve cylinder 24. At the rear end of the valve piston 27, a flange-shaped air introduction valve seat 31 projecting outward in the radial direction is integrally formed. An annular negative pressure introducing valve seat 32 is formed in the valve cylinder portion 24 and is arranged concentrically around the air introducing valve seat 31.

  The valve piston 27 is provided with a connection concave portion 33 that is opened at the center of the rear end surface of the air introduction valve seat 31. A ball joint 28a formed at the front end of the input rod 28 is fitted into the connection recess 33, and a part of the valve piston 27 is caulked so as to engage with the ball joint 28a. Is swingably connected to the valve piston 27.

  An expandable and contractible cylindrical valve body 34 having an annular valve portion 34 a is attached to the valve cylinder portion 24 by a valve holder 35. The valve body 34 is formed of an elastic material such as rubber, and an annular reinforcing plate 36 is embedded in the valve portion 34a.

  The valve portion 34a is disposed so as to be able to be seated on the atmosphere introduction valve seat 31 and the negative pressure introduction valve seat 32. A valve spring between the reinforcing plate 36 of the valve portion 34a and the input rod 28 for urging the valve portion 34a to the side for seating the air introduction valve seat 31 and the negative pressure introduction valve seat 32. The control valve 29 includes the air introduction valve seat 31, the negative pressure introduction valve seat 32, the valve body 34, and the valve spring 37.

  An input return spring 38 is contracted between the valve holder 35 and the input rod 28, and the input rod 28 is urged in a retreating direction by a spring force exerted by the input return spring 38, and the valve holder 35 35 is held at a fixed position in the valve barrel 24.

  A front annular chamber 39 surrounding the negative pressure introducing valve seat 32 is formed in the valve cylinder 24, and the front surface of the valve portion 34a faces the front annular chamber 39. The outer periphery of the valve portion 34a is slidably in close contact with the inner peripheral surface of the valve cylinder portion 24 behind the front annular chamber 39. Therefore, the front annular chamber 39 is closed when the valve portion 34a is seated on the negative pressure introduction valve seat 32. Further, a rear annular chamber 40 separated from the front annular chamber 39 is defined between the valve body 34 and the valve cylinder 24 so as to face the rear surface of the valve section 34a.

  The front annular chamber 39 communicates with the front negative pressure chamber 16 through the first passage 41 formed in the valve cylinder 24 and the inside of the boss 23, and branches off from the first passage 41 to form the front annular chamber 39. It communicates with the rear negative pressure chamber 20 via a second passage 42 provided in the valve cylinder 24. Further, the valve cylinder portion 24 has a third passage 43 formed so as to allow one end to pass through the rear working chamber 21 and to open the other end between the negative pressure introduction valve seat 32 and the atmosphere introduction valve seat 31. Provided.

  At a plurality of locations around the piston boss 25, cylindrical sleeves 45 made of a synthetic resin extending parallel to the piston boss 25 are arranged. The sleeve 45 has one end fixed to one of the partition plate 10 and the rear diaphragm 19 and airtightly penetrates the other of the partition plate 10 and the rear diaphragm 19. In this embodiment, The rear end, which is the one end of the sleeve 45, is fixed to the rear diaphragm 19, and the front end of the sleeve 45 passes through the partition plate 10 in an airtight manner.

  A tie rod 56 is hermetically passed through the sleeve 45 and fixed between the front shell half 7 and the rear shell 8 through the front booster piston 14 and the front diaphragm 15 in an airtight manner. An annular passage 44 is formed between the sleeve 45 and the tie rod 56 and connects the front working chamber 17 and the rear working chamber 21.

  The tie rod 56 has a male thread 57 at a front end thereof and a male thread 58 at a rear end thereof, and penetrates the front shell half 7 and the rear shell half 8. An annular stopper plate 59 is sandwiched between an annular projection 56a integrally provided near the front portion of the 56 and the front shell half 7, and a flange portion 56b integrally provided near the rear portion of the tie rod 56 is provided. The tie rod 56 is fixed between the front shell half 7 and the rear shell half 8 by being caulked to the rear shell half 8.

  The male thread portion 57 at the front end of the tie rod 56 is inserted into the flange portion 6a of the cylinder body 6, and a nut 61 with a washer 60 interposed between the flange portion 6a and the nut 61 is screwed into the male thread portion 57. As a result, the cylinder body 6 is attached to the front shell half 7, that is, the booster shell 5.

  The male screw portion 58 at the rear end of the tie rod 56 is inserted into a support portion S of a vehicle body or the like, and a nut 63 having a washer 62 interposed between the male screw portion 58 and the support portion S is screwed into the male screw portion 58. Thus, the rear shell half 8, that is, the booster shell 5 is attached to the support portion S.

  Referring to FIG. 2 as well, an annular grommet 65 is attached to the partition plate 10 to hermetically penetrate the front end of the sleeve 45, and the grommet 65 is resiliently provided on the outer periphery of the front end of the sleeve 45. It is slidingly contacted.

  In order to fix the rear end of the sleeve 45, an annular fitting portion 66 made of an elastic material is fixed to the rear diaphragm 19, and the inner periphery of the annular fitting portion 66 is fixed to the sleeve 45. The rear end portion of the sleeve 45 is fitted to the annular fitting portion 66 so as to resiliently contact the outer periphery of the rear end portion. In this embodiment, the annular fitting portion 66 is formed integrally with the rear diaphragm 19 so as to protrude toward the rear negative pressure chamber 20.

  3, the end of the sleeve 45 on the side of the rear diaphragm 19 has a cylindrical portion 45a fitted to the annular fitting portion 66, and a cylindrical portion 45a on the rear working chamber 21 side. A flange portion 45b projecting radially outward from an end portion and facing an end portion of the annular fitting portion 66 on the side of the rear working chamber 21; and a flange projecting radially outward from an outer periphery of the cylindrical portion 45a. A retaining protrusion 45c facing the end of the fitting portion 66 on the side of the rear negative pressure chamber 20 is provided integrally, and is provided on the outer periphery of the cylindrical portion 45a between the flange portion 45b and the retaining protrusion 45c. An annular fitting recess 67 for fitting the annular fitting portion 66 is formed.

  Incidentally, the tie rod 56 is integrally formed with a flange portion 56b which is fixed to the rear shell half 8 in contact with the inner surface of the rear shell half 8 and opposed to the flange portion 45b of the sleeve 45. The flange 45b has a larger diameter than the flange 56b. That is, the flange portion 45b is formed such that the outer diameter D2 of the flange portion 45b is larger than the outer diameter D1 of the flange portion 56b (D2> D1).

  At a plurality of positions (six in this embodiment) in the circumferential direction of the flange portion 45b, through holes 68 communicating with the annular passage 44 between the sleeve 45 and the tie rod 56 are provided. The outer end of the through hole 68 along the radial direction is disposed outside the outer periphery of the flange portion 56b on a projection onto a plane orthogonal to the axis of the sleeve 45 and the tie rod 56. That is, on a projection (FIG. 2) onto a plane including the axis of the sleeve 45 and the tie rod 56, a straight line L passing through the outer end of the through hole 68 along the radial direction of the flange 45b is It will pass outside than the outer circumference.

  At the end of the sleeve 45 on the front diaphragm 15 side, the front diaphragm 15 is attached to the front diaphragm 15 around a through hole 70 provided in the front booster piston 14 so as to penetrate the tie rod 56. An abutting pressing portion 45d is provided integrally with the booster piston 14 and abutting on the rear surface of the front diaphragm 15 while allowing air to flow between the annular passage 44 and the front working chamber 17.

  Moreover, the contact pressing portion 45d abuts on the rear surface of the front diaphragm 15 at a plurality of (for example, three) positions spaced apart in the circumferential direction of the end of the sleeve 45 on the front diaphragm 15 side. In this state, air is allowed to flow between the annular passage 44 and the front working chamber 17, and the abutting pressing portion 45 d having a slightly protruding shape is an end of the sleeve 45 on the front diaphragm 15 side. The unit is provided integrally.

  Further, the front diaphragm 15 is integrally formed with a seal portion 71 that is in airtight sliding contact with the outer periphery of the tie rod 56 on the front working chamber 17 side of the front booster piston 14.

  In the present embodiment, the seal portion 71 integrally includes two annular projecting portions 71a and 71b that protrude inward in the radial direction so as to be in airtight sliding contact with the outer periphery of the tie rod 56 and are spaced apart in the axial direction. The tie rod 56 is formed in a cylindrical shape, and has a cylindrical rear extending portion 71c whose tip end is slidably contacted with the outer periphery of the tie rod 56 in an airtight manner while being entirely inserted into the sleeve 45. The front ends of the annular projecting portions 71a, 71b and the rear extending portion 71c are hermetically slid on the outer periphery of the tie rod 56 closer to the front working chamber 17 than the front booster piston 14. Touch

  The seal portion 71 integrally has a front protruding portion 71d that penetrates through the through hole 70 of the front booster piston 14 and protrudes toward the front negative pressure chamber 16 side. Is formed in a cylindrical shape so that its outer periphery 71da extends in a straight line parallel to the axis of the sleeve 45 in a projection view (FIG. 2) onto a plane including the axis of the sleeve 45.

  Referring again to FIG. 1, the valve sleeve portion 24 is covered with a telescopic boot 46 whose front end is connected to the rear extension tube 8a, and the rear end of the boot 46 is attached to the input rod 28. At the rear end of the boot 46, an air inlet 47 communicating with the inside of the valve body 34 is provided.

  Further, a key 48 extending along a diameter line of the valve cylinder portion 24 at an axially intermediate portion of the guide hole 30 is attached to the valve cylinder portion 24 so as to define a retreat limit of the valve piston 27. .

  A circular concave portion 49 having a diameter larger than that of the guide hole 30 and being coaxial with the guide hole 30 is formed at the front end of the valve cylinder portion 24, and the front end of the valve piston 27 is brought into contact with the concave portion 49. An elastic body 50 such as rubber, which is formed in a disk shape so as to be obtained, is fitted into the recess 49. On the other hand, the rear end of the output rod 52 whose front end is connected to the piston rod 51 of the brake master cylinder M is inserted into the recess 49 with the elastic body 50 interposed between the output rod 52 and the valve cylinder 24. Is done. A coil-shaped valve barrel return spring 53 is contracted between the valve barrel 24 and the front shell half 7.

  Incidentally, at the rear end of the cylinder body 6 of the brake master cylinder M, a flange portion 6a and a cylindrical protrusion 6b projecting rearward from the flange portion 6a are integrally provided. At the center of the shell half 7, a short cylindrical portion 7 a having a bottom and forming an insertion hole 54 into which the cylindrical projection 6 b is inserted is inserted into the front negative pressure chamber 16. The front end portion of the valve barrel return spring 53 is in contact with the front shell half 7 so as to surround the base of the short cylindrical portion 7a.

  In the rest state of the tandem type negative pressure booster B, the front and rear booster pistons 14 and 18 and the input rod 28 are located at the respective retreat limits, and the rear end of the valve piston 27 is introduced into the atmosphere. While seating on the valve portion 34a of the valve body 34, the valve seat 31 presses the valve portion 34a to slightly separate from the negative pressure introducing valve seat 32. As a result, the negative pressure in the front and rear negative pressure chambers 16 and 20 is transmitted to the front and rear working chambers 17 and 21, and both chambers 16, 20: 17 and 21 have the same pressure. The pistons 14, 18 and the valve body 24 are held at the retracted positions by the urging force of the valve body return spring 53.

  When the brake pedal P is depressed at a normal speed to brake the vehicle, and the input rod 28 and the valve piston 27 are advanced, the valve cylinder portion 24 advances with the valve piston 27 held in the retracted position. I do. Therefore, the urging force of the valve spring 37 causes the valve body 34 to extend so that the valve portion 34a is seated on the negative pressure introduction valve seat 32. At the same time, the atmosphere introduction valve seat 31 is separated from the valve body 34, The air flowing into the valve cylinder 24 from the air inlet 47 passes through the air inlet valve seat 31 and is introduced into the front and rear working chambers 17 and 21, and the front and rear working chambers 17 and 21 are moved to the front. Since the pressure is made higher than that of the rear negative pressure chambers 16 and 20, the front and rear booster pistons 14 and 18 obtain the forward thrust based on the pressure difference between them, and the valve cylinder 24, the valve piston 27 and the output rod 52 accompany. The piston rod 51 of the brake master cylinder M is pushed forward by the output rod 52 while the piston rod 51 of the brake master cylinder M is pushed forward by the output rod 52.

  When assembling the sleeve 45 at the time of manufacturing the tandem type negative pressure booster B, a first step of attaching the grommet 65 to the partition plate 10 as shown in FIG. 4 and a second step as shown in FIG. , And the third step shown in FIG.

  In the second step shown in FIG. 5, the front diaphragm 15 connected to the rear surface of the front booster piston 14, the partition plate 10 to which the grommet 65 is attached, and the annular fitting portion 66 are integrally provided. Then, the rear diaphragm 19 connected to the rear surface of the rear booster piston 18 is assembled with each other. At this time, the front booster piston 14 and the front booster piston 14 are provided around the outer periphery of the front end of a cylindrical boss portion 23 slidably supported by the partition plate 10 with an annular seal member 22 interposed between the partition plate 10 and the partition plate 10. The front diaphragm 15 is connected, the rear booster piston 18 and the rear diaphragm 19 are connected to the outer periphery of the rear end of the boss 23, and the front end of the second cylindrical member 11 is attached to the outer periphery of the partition plate 10. The second outer bead portion 19a of the rear diaphragm 19 is sandwiched between the outer periphery of the first tubular member 9 and the inner periphery of the rear end of the second tubular member 11.

  6, in a third step, the sleeve 45 is inserted from the side of the rear diaphragm 19 as shown by an arrow 74, and is elastically fitted to an annular fitting portion 66 integral with the rear diaphragm 19, as shown in FIG. It is inserted through the grommet 65 attached to the partition plate 10.

  Next, the operation of this embodiment will be described. A booster shell 5 in which a front shell half 7 and a rear shell half 8 are connected to each other has a front shell chamber 12 and a rear shell chamber 13 inside the booster shell 5. A front diaphragm 15 supported by the booster shell 5 by partitioning the partition wall plate 10 and partitioning the inside of the front shell chamber 12 into a front front negative pressure chamber 16 and a rear front working chamber 17. Are connected to the rear surface of the front booster piston 14 and partition the inside of the rear shell chamber 13 into a front rear negative pressure chamber 20 and a rear rear working chamber 21 to be supported by the booster shell 5. Are fixed to the rear surface of the rear booster piston 18, and a sleeve 45 that hermetically passes through the partition plate 10 is fixed to the rear diaphragm 19, and the front shell half 7 and A tie rod 56 fixed between the rear shell halves 8 forms an annular passage 44 between the front working chamber 17 and the rear working chamber 21 with the sleeve 45 and is inserted through the sleeve 45. In the tandem-type negative pressure booster B, an annular seal portion 71 is formed integrally with the front diaphragm 15 on the front working chamber 17 side of the front booster piston 14 so as to be in airtight sliding contact with the outer periphery of the tie rod 56. Therefore, in securing an effective stroke of the front diaphragm 15 and the seal portion 71 to the side where the volume of the front negative pressure chamber 16 is reduced, the front booster piston 14 and the front shell half in a non-operating state are secured. The distance between the bodies 7 in the direction along the axis of the tie rod 56 can be made as short as possible. Make it possible to shorten the overall length of the beam-type vacuum booster B, it is possible to improve the mountability to the vehicle.

  Also, the rearward extending portion 71c fixed to the rear diaphragm 19 and entirely inserted into the sleeve 45 which is fixed to the rear diaphragm 19 and penetrates the partition plate 10 in an airtight manner is integrally formed on the seal portion 71. The contact position of the portion 71 with the tie rod 56 can be arranged more rearward, and the total length of the tandem-type negative pressure booster B in the direction along the axis of the tie rod 56 can be further reduced, so that it is mounted on a vehicle. Sex can be further enhanced.

  The front diaphragm 15 is sandwiched between the sleeve 45 and the front booster piston 14 around a through hole 70 provided in the front booster piston 14, and the annular passage 44 and the front working chamber 17 are interposed therebetween. Since the contact pressing portion 45d which comes into contact with the rear surface of the front diaphragm 15 while allowing the air to flow therethrough is provided integrally, the front diaphragm 15 pressed by the contact pressing portion 45d at the time of operation is the front portion. It operates together with the booster piston 14, so that the front booster piston 14 is prevented from falling out of the front diaphragm 15, and the formation of the contact pressing part 45d allows the front passage chamber 45 to move between the annular passage 44 and the front working chamber 17. The air circulation is not hindered.

  In addition, the seal portion 71 formed integrally with the front diaphragm 15 has a front protruding portion 71d that penetrates the through hole 70 and protrudes toward the front negative pressure chamber 16 side. The portion 71d does not require the front projecting portion 71d to have a function of suppressing the front booster piston 14 from coming out of the front diaphragm 15, and the front projecting portion 71d includes the axis of the sleeve 45. The projection is formed in a cylindrical shape having an outer periphery 71da extending linearly in parallel with the axis of the sleeve 45 on a projection view onto a plane, so that the front portion when the seal portion 71 is molded together with the front diaphragm 15 is formed. The productivity of the projecting portion 71d can be improved by improving the die-cutting property, and the material of the front diaphragm 15 and the seal portion 71 can be improved. In it increases the hardness of the rubber, it is possible to improve the wear resistance.

  Further, since the abutting pressing portions 45d are provided at a plurality of circumferentially spaced positions on the front end of the sleeve 45 on the side of the front diaphragm 15, the passage for connecting the annular passage 44 to the front working chamber 17 is provided. Can be easily formed between the plurality of contact pressing portions 45d.

  An annular grommet 65 attached to the partition plate 10 is elastically slidably contacted with the outer periphery of the sleeve 45, and is fitted to an annular fitting portion 66 made of an elastic material fixed to the rear diaphragm 19. Since the sleeve 45 is fitted so that the inner periphery of the joint portion 66 is resiliently brought into contact with the outer periphery of the sleeve 45, compared with the case where the sleeve 45 is press-fitted and assembled to the rear diaphragm 19, Assemblability is improved, and as a result, mass productivity can be improved. Moreover, it is not necessary to limit the material of the sleeve 45 to metal, and the degree of freedom in selecting the material of the sleeve 45 can be increased.

  The annular fitting portion 66 is formed integrally with the rear diaphragm 19, and the sleeve 45 is formed of a cylindrical portion 45 a that fits into the annular fitting portion 66, and the cylindrical portion 45 a on the side of the rear diaphragm 19. A flange portion 45b projecting radially outward from an end of the annular fitting portion 66 and facing an end of the annular fitting portion 66 on the rear working chamber 21 side; and projecting radially outward from an outer periphery of the cylindrical portion 45a. An annular retaining projection 45c facing an end of the annular fitting portion 66 on the rear negative pressure chamber 20 side; and an outer periphery of the cylindrical portion 45a between the flange 45b and the retaining projection 45c. Since the annular fitting recess 67 for fitting the annular fitting portion 66 is formed in the sleeve 45, it is possible to reliably prevent the sleeve 45 from coming out of the rear diaphragm 19 during operation.

  The tie rod 56 is fixed to the rear shell half 8 at the end on the rear shell half 8 side, facing the flange portion 45b of the sleeve 45 while contacting the inner surface of the rear shell half 8. A flange 68b is integrally formed, and a plurality of through-holes 68 communicating with the annular passage 44 are provided at a plurality of circumferential positions of the flange 45b having a larger diameter than the flange 56b. Since the outer end of the through hole 68 along the radial direction is disposed outside the outer periphery of the flange portion 56b on a projection view on a plane orthogonal to the axis of the tie rod 56 and the sleeve 45, the manufacturing process is completed. Even if the flange portion 45b abuts on the flange portion 56b due to tolerance at the time, the flange portion 45b is provided at a plurality of circumferential positions of the flange portion 45b having a larger diameter than the flange portion 56b. The outer end of the through-hole 68 communicating with the annular passage 44 in the outside 45 is located outside the outer periphery of the flange portion 56b on a projection on a plane orthogonal to the axis of the tie rod 56 and the sleeve 45. The space between the rear working chamber 21 and the annular passage 44 is not interrupted.

  Moreover, since the sleeve 45 is made of resin, the cost can be reduced.

  Further, in assembling the sleeve 45, a first step of attaching the grommet 65 to the partition plate 10; a front diaphragm 15 attached to a rear surface of the front booster piston 14, and the grommet 65 attached. A second step of mutually assembling the partition plate 10 and a rear diaphragm 19 bonded to the rear surface of the rear booster piston 18 while integrally having the annular fitting portion 66; and attaching the sleeve 45 to the rear diaphragm 19. And a third step of resiliently fitting the annular fitting portion 66 and inserting the grommet 65 through the grommet 65 in this order, thereby realizing a simple and highly mass-producing assembling method. it can.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

  For example, in the above-described embodiment, the sleeve 45 is fixed to the rear diaphragm 19 and penetrates the partition plate 10 in an airtight manner. However, in the present invention, the sleeve 45 is fixed to the partition plate 10. The present invention can be applied to a tandem type negative pressure booster having a structure in which the rear diaphragm 19 penetrates airtightly.

5 Booster shell 7 Front shell half 8 Rear shell half 10 Partition plate 12 Front shell chamber 13 Rear shell chamber 14 Front Booster piston 15 Front diaphragm 16 Front negative pressure chamber 17 Front working chamber 18 Rear booster piston 19 Rear diaphragm 20 Rear negative pressure chamber 21 -Rear working chamber 44-Annular passage 45-Sleeve 45a-Cylindrical part 45b-Flange part 45c-Retaining projection 56-Tie rod 56b-Flange part 65- Annular grommet 66 Annular fitting part 67 Fitting concave part 68 Through hole

Claims (5)

  A booster shell (5) in which the front shell half (7) and the rear shell half (8) are combined, and a front shell chamber (12) and a rear shell chamber (13) inside the booster shell (5). A partition plate (10) coupled to the booster shell (5) while partitioning the front shell chamber; a front booster piston (14) housed in the front shell chamber (12) so as to be able to reciprocate back and forth; The interior of the shell chamber (12) is divided into a front-side front negative pressure chamber (16) and a rear-side front working chamber (17) while being bound to a rear surface of the front booster piston (14) and the booster. A front diaphragm (15) supported by the shell (5), a rear booster piston (18) housed in the rear shell chamber (13) so as to be able to reciprocate back and forth, and a front side inside the rear shell chamber (13). Rear negative pressure chamber (20) and A rear diaphragm (19) bound to the rear surface of the rear booster piston (18) while being partitioned into a rear working chamber (21) on the side and supported by the booster shell (5); and the partition plate (10). A cylindrical sleeve (45) fixed to one of the rear diaphragms (19) and airtightly penetrating the other of the partition plate (10) and the rear diaphragm (19); and the front working chamber (17). ) And an annular passage (44) connecting between the rear working chamber (21) and the sleeve (45) and inserted through the sleeve (45), and the front shell half (7) and A tandem-type negative pressure booster comprising a tie rod (56) fixed between the rear shell halves (8), wherein the partition plate (10) and the rear diaphragm (19) are provided. An annular grommet (65) attached to the other is resiliently slidably contacting the outer periphery of the sleeve (45), and is fixed to the one of the partition plate (10) and the rear diaphragm (19). The sleeve (45) is resiliently contacted with the annular fitting portion (66) made of an elastic material such that the inner periphery of the annular fitting portion (66) elastically contacts the outer periphery of the sleeve (45). A tandem type negative pressure booster characterized by being fitted.   The annular fitting portion (66) is integrally formed with the rear diaphragm (19), and the sleeve (45) includes a cylindrical portion (45a) fitted to the annular fitting portion (66); A flange portion which protrudes radially outward from an end of the cylindrical portion (45a) on the side of the rear diaphragm (19) and faces an end of the annular fitting portion (66) on the side of the rear working chamber (21). 45b) and an annular retaining projection projecting radially outward from the outer periphery of the cylindrical portion (45a) and facing the end of the annular fitting portion (66) on the side of the rear negative pressure chamber (20). (45c), wherein the annular fitting portion (66) is fitted to the outer periphery of the cylindrical portion (45a) between the flange portion (45b) and the retaining projection (45c). 2. The method according to claim 1, wherein a recess is formed. Tandem-type negative pressure booster.   The end of the tie rod (56) on the side of the rear shell half (8) faces the flange portion (45b) of the sleeve (45) while abutting on the inner surface of the rear shell half (8). A flange portion (56b) fixed to the rear shell half (8) is integrally formed, and the flange portion (45b) formed at a larger diameter than the flange portion (56b) is provided at a plurality of circumferential positions. A through-hole (68) communicating with the annular passage (44) is provided, and the outer end of the through-hole (68) along the radial direction of the flange portion (45b) is connected to the tie rod (56) and the sleeve (45). The tandem-type negative pressure booster according to claim 2, wherein the tandem-type negative pressure booster is disposed outside the outer periphery of the flange portion (56b) on a projection onto a plane orthogonal to the axis.   The tandem type negative pressure booster according to any one of claims 1 to 3, wherein the sleeve (45) is made of resin.   A method for assembling the sleeve when manufacturing the tandem-type negative pressure booster according to any one of claims 1 to 4, wherein the grommet (65) is attached to the partition plate (10). A front diaphragm (15) attached to a rear surface of the front booster piston (14), the partition plate (10) to which the grommet (65) is attached, and the annular fitting portion (66). A second step of mutually assembling a rear diaphragm (19) attached to a rear surface of the rear booster piston (18) while integrally incorporating the sleeve (45) from the rear diaphragm (19) side. A third step of resiliently fitting to the annular fitting portion (66) by insertion and inserting the grommet (65) into the grommet (65) in this order. Breakfast assembling method.

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